[users] Program ANI or PTT ID?

I'm having a devil of a time figuring out how to do this... I'm looking through all sorts of fields and functions looking for anything that looks relevant. All I can find is length (3, 4, or 5) and PTT-ID that isn't a way to set the code, but just when it's transmitted. I was given a 4 digit code that is now a requirement on one of the repeaters I use, but no info on how to apply it.