Differentiating between domain and local groups for WindowsBuiltInRole

[WhelanKerry]

I am using WindowsBuiltInRole.XXXX to retrieve the role of the user.
This is successful in that it retrieves that I am a user on the
domain, however it also detects that I am an administrator, as I am
the admisitrator to my own machine. Is it possible to differentiate
between an administrator to the domain and administrator to the local
machine.

Also can WindowsBuiltInRole be used in a workgroup?

Thankyou in advance

Kerry Whelan