You dont even need to check for a group really....WHy not just do IF/Endifs's for each user?

Code:

; Some User
If @UserID = "someuser"
   USE P: "\\someserver\share"
   USE S: "\\anotherserver\SHARED"
Endif

; Another User
If @UserID = "anotheruser"
   USE P: "\\someserver\share"
   USE S: "\\anotherserver\SHARED"
Endif