I'm trying to get this to work in powershell:
$spListItem[$ppField] = "domain\username" $spListItem.Update()
This gives me the following error: Exception calling "Update" with "0" argument(s): "Invalid data has been used to update the list item. The field you are trying to update may be read only."
I know by that SharePoint is expecting something like "3;domain\username"
What's the easiest way to get this? I hope I don't have to iterate over the full SPUserCollection..