Maybe a second optional parameter to specify a user or computer account would be an option. If not specified check the user account.

;Second parameter not given so use default and check the user account.
If InGroup("SomeUserGroup")
	?"User is a member."

;Second parameter is given so check the computer account.
If InGroup("SomeComputerGroup", 1)
	?"Computer is a member."

- Chuck Norris once sold ebay to ebay on ebay.