Automaticly put a mailadresse in Copy on answered in a ticket.

Hi. 

I would need some help to do a task in the service portal. 

One of our customer would like that when we answered in a ticket it will automaticly go an answered in copy to a another mailadress as well as the reciepient. 
I think this is something that could be fixed with a macro but I dont know with parameters that is correct to use for this. 
Does anyone has done this before and know how to make this?