It should already be writing the Username and Computername to the central INI file via this these lines...
 Code:
$null = WriteProfileString($collectionfile,$grouptocheckfor,@UserID,@WkSta)
$null = WriteProfileString($collectionfile,"Non-"+$grouptocheckfor,@UserID,@WkSta)

Assuming that you're talking about the code that I posted anyways.