UID access from CCK userreference.module to CCK compute example

I've been searching for an example of getting the UID out of the CCK user reference module and used in the CCK compute module with no luck. Either I'm searching for the wrong stuff, in the wrong places, or an example of this is not out there. Can anyone help me out?

A generic example is fine, but my specific need is to take the 2 users selected from the cck user reference module and on the same node compute a field that takes the first and last names from a custom profile and concatenates them.