Find all RDP sessions on servers using a PowerShell function to wrap the Query Session logic. NB: Alternate Credentials not yet implemented

Get-RdpSessions.ps1

function Get-RdpSessions {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory=$true, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true)]
        $ComputerName
        ,
        [Parameter()]
        [switch]$Force
        <# not yet implememnted
        ,
        [Parameter()]
        [System.Management.Automation.Credential()]
        [System.Management.Automation.PSCredential]$Credential = [System.Management.Automation.PSCredential]::Empty
        #>
    )
    process {

        #force logic
        [bool]$forced = $false
        [string]$previousValue = '' #hold as string in case this property's held as something other than int; i.e. we don't want to cause side effects
        if ($Force.IsPresent) {
            try {
                $previousValue = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $ComputerName).OpenSubKey('SYSTEM\CurrentControlSet\Control\Terminal Server').GetValue('AllowRemoteRPC') 
                write-verbose "$ComputerName's AllowRDP = $previousValue"
                if($previousValue -ne '1') {
                    [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $ComputerName).OpenSubKey('SYSTEM\CurrentControlSet\Control\Terminal Server',$true).SetValue('AllowRemoteRPC', 1)
                    $forced = $true
                    write-verbose "$ComputerName's AllowRDP Forced to 1"
                }
            } catch {
                write-verbose "$ComputerName's AllowRDP failed to use the force :("
                #even if we fail here, we still proceed; as we may be able to see sessions on the remote machine even if we can't read from its registry
            }
        }


        #query session logic
        try {
            #https://ss64.com/nt/query-session.html
            #pull the results into a variable
            [string[]]$querySessionResult = (qwinsta "/server:$ComputerName") 
            #it would be nice to figute out the fixed-width column sizes automatically, in case they vary; but as the ID column is right aligned, that's not so easy:
            #[string]$regex = '^' + (($querySessionResult[0] -split '\s\b' | select -skip 1 | %{"(?<$($_.trim())>.{$($_.Length+1)}"}) -join ')') + '.*)$'
            #so instead using a fixed defintion:
            [string]$regex = '^(?<SESSIONNAME>.{18})(?<USERNAME>.{18})(?<ID>.{11})(?<STATE>.{8})(?<TYPE>.{7})(?<DEVICE>.*)$' #column sizes from https://superuser.com/a/1000089/156700
            $querySessionResult | select -skip 1 | ?{$_ -match $regex} | %{
                $matches.remove(0)
                $properties = @{}
                $Matches.Keys | %{$properties[$_] = "$($Matches[$_])".Trim()}
                (New-Object -TypeName PSObject -Property $properties)
            }
        } finally { #regardless of whether the above works, ensure that if we forced things, we put them back how they were
            if($forced) {
                [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $ComputerName).OpenSubKey('SYSTEM\CurrentControlSet\Control\Terminal Server',$true).SetValue('AllowRemoteRPC', $previousValue)
                write-verbose "$ComputerName's AllowRDP reset to $previousValue"
            }
        }
    }
}

#demo for one computer
Get-RdpSessions -ComputerName $MyComputer -Force -Verbose

#demo for all servers in AD:

#uses Test-ConnectionQuickly workflow from here to avoid running against offline machines https://codereview.stackexchange.com/questions/97726/powershell-to-quickly-ping-a-number-of-machines
$servers = Get-AdComputer {(OperatingSystem -like "*server*") -and (Enabled -eq $true)} 
$servers = Test-ConnectionQuickly $servers | ? Online
$servers | Get-RdpSessions -Force -Verbose | ? Username