Import-Module ActiveDirectory
$Users = Import-Csv -Delimiter ";" -Path ".userslist.csv"
foreach ($User in $Users)
{
    $OU = "OU=pfsense,DC=tech,DC=local"
    $Password = $User.password
    $Detailedname = $User.firstname + " " + $User.name
    $UserFirstname = $User.Firstname
    $FirstLetterFirstname = $UserFirstname.substring(0,1)
    $SAM =  $FirstLetterFirstname + $User.name
    New-ADUser -Name $Detailedname -SamAccountName $SAM -UserPrincipalName $SAM -DisplayName $Detailedname -GivenName $user.firstname -Surname $user.name -AccountPassword (ConvertTo-SecureString $Password -AsPlainText -Force) -Enabled $true -Path $OU
}

Name;Firstname;Password
MILLE;Thierry;P@$$w0rd!1
MILLE;Vendelin;P@$$w0rd!2
MILLE;Blandine;P@$$w0rd!3