function Fetch-ADUser {
    Param (
    [parameter(ValueFromPipeline=$true)]
    [hashtable]$Properties,
    [parameter(ParameterSetName='Identity',Position=0)]
    [string]$Identity,
    [parameter(ParameterSetName='Name',Position=0)]
    [string]$GivenName,
    [parameter(Position=1)]
    [string]$Surname
    )
    $parameter = @{}
    if ($allprops) {
        $parameter = '@{Properties="*"}'
    }else{
        $propstr = @()
        if ($Properties.Count) {
            $propstr = "@("
            $Properties.Keys | %{
                $propstr += "`"$_`","
            }
            $propstr = $propstr.TrimEnd(',')+")"
            $parameter.Add('Properties',$propstr)
        }
    }

    switch ($PsCmdlet.ParameterSetName) {

        "Identity" {
            $parameter | Get-ADUser -Identity $Identity
        }
        "Name" {
            "*******"
            #Works!
            Get-ADUser -Filter {(GivenName -eq $givenname) -And (Surname -eq $surname)} -Properties @("mail","info")
            #Fail!
            $parameter | Get-ADUser -Filter {(GivenName -eq $givenname) -And (Surname -eq $surname)}
            Get-ADUser -Filter {(GivenName -eq $givenname) -And (Surname -eq $surname)} $parameter
            "******"
        }
    }
}

$newprop = @{info="pers3232323pere";mail="petrfeaf@fdadf.com"}
$user = $newprop | Fetch-ADUser -GivenName 'Pär' -Surname 'Halleröd'


######################
OUTPUT
######################
Get-ADUser : The input object cannot be bound to any parameters for the command either because the command does not take pipeline input or
operties do not match any of the parameters that take pipeline input.
At D:\Scripts\elevimport\MasterADManager.ps1:43 char:28
+                 $parameter | Get-ADUser <<<<  -Filter {(GivenName -eq $givenname) -And (Surname -eq $surname)}
    + CategoryInfo          : InvalidArgument: (System.Collections.Hashtable:Hashtable) [Get-ADUser], ParameterBindingException
    + FullyQualifiedErrorId : InputObjectNotBound,Microsoft.ActiveDirectory.Management.Commands.GetADUser

Get-ADUser : A positional parameter cannot be found that accepts argument 'System.Collections.Hashtable'.
At D:\Scripts\elevimport\MasterADManager.ps1:44 char:15
+                 Get-ADUser <<<<  -Filter {(GivenName -eq $givenname) -And (Surname -eq $surname)} $parameter
    + CategoryInfo          : InvalidArgument: (:) [Get-ADUser], ParameterBindingException
    + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.ActiveDirectory.Management.Commands.GetADUser

*******


DistinguishedName : CN=Pär Halleröd,OU=Praktikanter,OU=Tegner,OU=0_Users,OU=Skolor,DC=saffle,DC=edu
Enabled           : True
GivenName         : Pär
info              : testnote
mail              : Par.Hallerod@skola.saffle.se
Name              : Pär Halleröd
ObjectClass       : user
ObjectGUID        : d004bb22-bb0c-4d6e-9a70-d6956c39757e
SamAccountName    : 1101paol
SID               : S-1-5-21-448539723-1604221776-839522115-17256
Surname           : Halleröd
UserPrincipalName : 1101paol@saffle.edu

DistinguishedName : CN=Pär Halleröd,OU=Praktikanter,OU=Tegner,OU=0_Users,OU=Skolor,DC=saffle,DC=edu
Enabled           : True
GivenName         : Pär
Name              : Pär Halleröd
ObjectClass       : user
ObjectGUID        : d004bb22-bb0c-4d6e-9a70-d6956c39757e
SamAccountName    : 1101paol
SID               : S-1-5-21-448539723-1604221776-839522115-17256
Surname           : Halleröd
UserPrincipalName : 1101paol@saffle.edu

******