I need help but I don't know what to name this

[DivineMessenger]

What I want to do is put user's real names in parenthesis next to their username on the user's online list.

Example:

Users Online: DivineMessenger (Dexter),

There is currently a user field for names so I want to link that in next to their username somehow. Is this doable?

[Dismounted]

Edit the template forumhome_loggedinuser.