My b2evolution Version: 2.4.

Hi,
I'm looking to find file/line where I could modify identity shown (I think it's word used in english).
For now, I have :
First Name, Last Name
But I want
First Name Last Name (Nickname)
I want to use this field as a "signature". I think it's easier than trying to create a new field. It will display for each user their name + their region in bracket.
Thanks!
Mel