$proc = (WmiObject Win32_Process -Filter "Name = 'w3wp.exe'" | Where-Object {$_.CommandLine -like "*SomeTextFromCl*"})
$id = $proc.ProcessId
$ws = [math]::round((Get-Process -Id $id).WS/1MB)
Write-Host $ws

Cannot bind argument to parameter 'Id' because it is null.
+ CategoryInfo          : InvalidData: (:) [Get-Process], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.GetProcessCommand
+ PSComputerName        : RemoteServerName

Invoke-Command -ComputerName RemoteServerName -FilePath script.ps1 -Credential $mycredential