Adding user profile fields to "Assign to" form

I am looking for possibility of using other custom fields taken from user profiles (like Name, Surname etc.) instead of just user name (i.e. his/her login) for "Assign to" form when creating new cases.
I was trying to add these custom fields to casetracker_assignee_options view to no avail. So I guess the only option is to PHP it directly into Case Tracker module itself. Any ideas?