New-WelcomeLetter

    #requires -Modules ActiveDirectory
    <#
    .Synopsis
       Creates a welcome letter from a template
    .DESCRIPTION
       Creates a welcome letter from a temaplte, looks up active directory for user info then does string and hyperlink replacements on a template word document
    .EXAMPLE
       New-WelcomeLetter -SamAccountName 'ExampleUser'
    .EXAMPLE
       New-WelcomeLetter -SamAccountName 'ExampleUser' -NewPassword -Verbose
    .EXAMPLE
       New-WelcomeLetter -SamAccountName 'ExampleUser' -NewPassword -ChangePasswordAtNextLogon -Verbose
    .AUTHOR
        Created by /u/Sys_Ad_MN edited and turned into a function by /u/CSTW
    #>
    function New-WelcomeLetter
    {
        [CmdletBinding()]
        [Alias()]
        [OutputType([string])]
        Param
        (
            # One or more SamAccountNames to generate a welcome letter for.
            [Parameter(Mandatory=$true,
                       ValueFromPipeline=$true,
                       Position=0)]
            [string[]]$SamAccountName,

            # Path to the template file that the replacments will be made on
            [ValidateScript({test-path $_})]
            [string]$Template = 'C:\temp\WelcomeLetters\Template.docx',

            # Directory where Welcome letters are saved
            [ValidateScript({test-path $_})]
            [string]$OutputDirectory = 'C:\temp\WelcomeLetters\',

            # Generates a new password and sets in Active Directory, if not specifed a generic message is used instead
            [Switch]$NewPassword,

            # Enables the "Change password at next logon" setting in Active Directory. Has no effect unless -NewPassword if specified
            [Switch]$ChangePasswordAtNextLogon
        )

        Begin
        {
            #Variables for string replacements
            $Forward = $True
            $MatchCase = $True
            $MatchWholeWord = $true
            $MatchWildcards = $False
            $MatchSoundsLike = $False
            $MatchAllWordForms = $False
            $wdReplaceNone = 0
            $wdFindContinue = 1
            $wdReplaceAll = 2
            $Wrap = $wdFindContinue
            $Format = $False
        }
        Process
        {
            #Foreach and process block to allow for the $Samaccountname to be either piped in or supplied as an array
            foreach($User in $SamAccountName) {
                Write-Verbose ""
                Write-verbose "Generating Welcome letter for $User"
                Write-Verbose ""
                #Get AD user details for replacements
                try
                {
                    Write-Verbose "Getting user details from Active Directory"
                    $ADUser = get-aduser $User -Properties EmailAddress, Title -ErrorAction Stop
                }
                catch
                {
                    Write-Warning "Unable to get user details from Active Directory, Skipping Welcome letter creation for $User"
                    Continue
                }
                #Assign this to make for easier formatting of verbose and warning messages
                $SamAccountName = $ADUser.SamAccountName

                #If the NewPassword parameter was specified generate a password, otherwise uses the default text
                if($PSBoundParameters.ContainsKey('NewPassword')) {

                    #Generate password
                    try
                    {
                        Write-Verbose 'Generating new password'
                        #Excluded some months to make minimum password length 10 charachters with only 4 numbers.
                        $Words = 'Summer', 'Winter','Autumn', 'Spring', 'January', 'February','August', 'September', 'October', 'November','December'
                        $Random = New-Object System.Random
                        $Word = $Words[$Random.Next(0,$Words.Count)]
                        $Number = Get-Random -Minimum 1000 -Maximum 9999
                        $Password = "$Word$Number"
                        $SecurePassword = ConvertTo-SecureString -string $Password -AsPlainText -Force
                    }
                    catch
                    {
                        Write-Warning "Failed to generate password. Skipping Welcome letter creation for $SamAccountName. `n`nError: $($Error[0])"
                        Continue
                    }

                    #Set account password in Active Directory
                    try
                    {
                        Write-Verbose "Setting password in Active Directory for $SamAccountName"
                        Set-ADAccountPassword -Identity $ADUser.SamAccountName -NewPassword $SecurePassword -Reset -whatif
                        Write-Verbose "Successfully set password in Active Directory"

                        if($PSBoundParameters.ContainsKey('ChangePasswordAtNextLogon')) {
                            try
                            {
                                Write-Verbose "Setting ChangePasswordAtLogon option in Active Directory"
                                $ADUser | Set-ADUser -ChangePasswordAtLogon $True
                            }
                            catch
                            {
                                Write-Warning "Failed to set change password at next logon option for $SamAccountName"
                            }
                        }
                    }
                    catch
                    {
                        Write-Warning "Failed to set account password. Using default text for password. `n`nError: $($Error[0])"
                        $Password = 'If you have not been given your password please contact the Helpdesk'
                    }
                }
                else #NewPassword parameter not specified
                {
                    $Password = 'If you have not been given your password please contact the Helpdesk'
                }

                [string]$OutputFilePath = join-path $OutputDirectory "$($ADUser.SamAccountName).docx"

                $Replacements = @{'#FirstName#' = $ADUser.GivenName
                                  '#LastName#'  = $ADUser.Surname
                                  '#Title#'     = $ADUser.Title
                                  '#PassWord#'  = $Password
                                  }


                #Create a new Com object, load the template and assign the selection to a variable
                try
                {
                    Write-Verbose "Opening Word template"
                    $WordObject = New-Object -comobject Word.Application -ErrorAction Stop -verbose:$False
                    $WordObject.Visible = $True
                    $DocumentObject = $WordObject.Documents.Open($Template) #path to word doc template
                    $SelectionObject = $WordObject.Selection

                }
                catch
                {
                    Write-Warning "Unable to open the template file: $Template, Skipping Welcome letter creation for $SamAccountName"
                    Continue
                }

                #Make string replacements
                foreach($Key in $Replacements.Keys) {
                    Write-Verbose "Replacing string $Key"
                    try
                    {
                        $FindText = $Key
                        $ReplaceWith = $Replacements.$Key

                        $MakeReplacement = $SelectionObject.Find.Execute($FindText,$MatchCase,$MatchWholeWord,$MatchWildcards,$MatchSoundsLike,$MatchAllWordForms,$Forward,$Wrap,$Format,$ReplaceWith,$wdReplaceAll)

                        if($SelectionObject.Find.Found)
                        {
                            Write-Verbose "String was replaced with: $ReplaceWith"
                        }
                        else
                        {
                            Write-Warning "Did not find the string $Key in the template: $Template"
                        }
                    }
                    catch
                    {
                        Write-Warning "Failed string replacement in template file: $Template for string: $Key"
                    }
                } #end foreach $Replacements.Keys

                #Edit the hyperlinks of email addresses
                $OldHyperlink = “mailto:#EmailAddress#”
                $NewHyperlink = "Mailto:$($ADUser.EmailAddress)"

                Write-Verbose "Replacing hyperlinks with email address: $($ADUser.EmailAddress)"
                foreach($HyperLinkObject in $DocumentObject.Hyperlinks) {
                    if($HyperLinkObject.address -eq $OldHyperlink)
                    {
                        $HyperLinkObject.Address = $HyperLinkObject.Address -Replace $OldHyperlink, $NewHyperlink
                    }
                }

                #Save the document
                try
                {
                    Write-Verbose "Saving welcome letter to $OutputFilePath"
                    $DocumentObject.SaveAs([ref] $OutputFilePath)
                }
                catch
                {
                    Write-Error "Failed to save the new Word document. `n`nError: $($Error[0])"
                }

                #Close the document
                try
                {
                    Write-Verbose "Closing Word docuemnt"
                    $WordObject.quit()
                }
                catch
                {
                    Write-Warning "Failed to close Word document. `n`nError: $($Error[0])"
                    Continue
                }

            } #end foreach samaccountname
        }
        End
        {
            Write-Output $OutputFilePath
        }
    }