Powershell: Bereits bestehenden Benutzer individuelle Passwörter zuweisen

#
# Script: ResetPwd.ps1
# Description: Reset the password for bulk number of users, and 
# set the property to change passwrod required at next logon
#
# 
#

Import-Module ActiveDirectory

# Set the default password
$password = ConvertTo-SecureString -AsPlainText “rau@2018” -Force 
 
# Get the list of accounts from the file on file
# List the user names one per line
#$users = Get-ADUser -SearchBase “OU=L-Konstruktion,OU=Users,OU=RAUEXT,OU=RAU,DC=rauglobal,DC=local” -Filter * | Select givenName > C:\Users\admgb\users.txt
gc C:\Users\admgb\users.txt | sort | get-unique > C:\Users\admgb\userlist.txt
$userlist = Get-Content -Path C:\Users\admgb\userlist.txt
do
{
$nummer = 3;

$Password1 = "RAUKO0@$nummer"  
$Password2 = "RAUKO@$nummer"  
$line = $userlist | Select -Index $nummer

ForEach ($user in $userlist)
{
  
    # Set the default password for the current account
    if($nummer -lt 10)
    {
        Set-ADAccountPassword -Identity "CN=$line,OU=L-Konstruktion,OU=Users,OU=RAUEXT,OU=RAU,DC=rauglobal,DC=local" -Reset -NewPassword (ConvertTo-SecureString -AsPlainText $Password1 -Force)       
        Write-Host “Passwort wurde für den Folgenden Benutzer zurückgesetzt: $user”
        Write-Host "Das neue Passwort ist: $Password1"  
    }
    elseif ($nummer -gt 10)
    {
         Set-ADAccountPassword -Identity "CN=$line,OU=L-Konstruktion,OU=Users,OU=RAUEXT,OU=RAU,DC=rauglobal,DC=local" -Reset -NewPassword (ConvertTo-SecureString -AsPlainText $Password2 -Force)       
        Write-Host “Passwort wurde für den Folgenden Benutzer zurückgesetzt: $user”
        Write-Host "Das neue Passwort ist: $Password2"  
    }
}
$nummer++
}while($nummer -lt $user)
# ————- End ———– 

Cannot convert value "kon_20" to type "System.Int32". Error: "Input string was   
not in a correct format."  
At C:\Users\admgb\Untitled1.ps1:44 char:1
+ $nummer++
+ ~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) , RuntimeException
    + FullyQualifiedErrorId : InvalidCastFromStringToInteger