Need the steps to create or see if possible to have a user log into another phone with a different profile to access their numbers and answer their phone at a different desk.
I assume you're talking about EM, since there's no mention of call agent i'll go with CUCM 7.X
Cisco Extension Mobility
Overview provides an explanation of what happens when a UDP logs into a phone that is not the same model and what is required.
I'd recommend you to read the whole doc.
if this helps, please rate