Please excuse my noobiness but I'm not exactly sure how to do what you're asking. If you could explain more in-depth I'd be very grateful.
Also I found a script on this page which makes all nicks bold but they are only black, it doesn't allow nick colours at the same time:
http://crrpg.com/forums/mirc-scripts/%28bobbold%29-bold-nicks-%28ingame-nicks-and-irc-nicks%29/
Not sure if there is something I'd need to alter in the script to make it function the way I'd want it to.
