A group of cc

I need to have a constant group of cc for the registered users.That constant groups should only be changed by admin,that the constant group varies to each and every users i.e some have the same registered users and the others have different users.

I am trying to develop a intranet site where only our techs could communicate with in their team and not as private,it should be a public chat.So I thought that if I can have a constant cc to each teams so if we can assign a static cc's.It would be like group chat.If its possible to chat only within the teams will also be soo good.
Is there any way i can do it.

Have you tried the Contact lists? You can create Global (accessible by all), Restricted (accessible by users already on the list) and Normal (accessible by owner only) distribution lists which should do the job.