Probably not possible but just thought I ask

I was wondering if I can set or add a regular phone extension to ring when an incoming call comes into the ACD (customer service line). A customer service is out and need someeone to help answer calls. He dont want to sit where the call master III is either. But the problem is that the customer service is in an ACD pool and have to logg into their phones to get logged into the bcms. The phone type is a callmaster III. I know it is probably not possible, but is it possible if I were to add that one user into the customer service hunt group and pickup group and he/she will be able to get or see the call also when the call comes in through that 800 number.
Also will it be recorded in the bcms for testing purpose because the extenstion is in along with the customer service huntgroup you think.
I know I dont make much sense here but is it possible and have anyone tried it before.