Using a "where" type clause

Is there a way to write a calculation that would pull an attribute from a group where the group is specified?

Here is what I need:

On the "Add Reminder" I need a calculation on User that would pull a supervisor field from the Support group where group name = Help Desk.  Is this an easy calc?

I would think it's something like:

return Group.Groups._Supervisor.Title where Group.Groups.Title == 'Help Desk'

Any advice?

Thanks!