Service Desk Service Catalogue form designer

Service Desk Service Catalogue form designer

I'm trying to design a custom user request form (this applies to any form being created though). Is it possible to have a drop down of the departments listed else where in the database? ie.

Firstname: Joe
Lastname: Bloggs
Department: < non-editable list of departments taken from the admin section of the service desk >

This seems like a pretty straight forward and common need but I'm unable to find any documentation or help on the subject, any assistance appreciated.

-Simon