How do we want CC list or commenter "does not match" to work??

[Joel Peshkin]

I am looking for input from the development team on bug 226434.
http://bugzilla.mozilla.org/show_bug.cgi?id=226434

Today, a search for CC list member doesn't match justdave, will return 
every bug on which someone other than justdave is copied and there seems 
to be no way to express that I am looking for bug on which justdave is 
not copied.

I believe I can teach Search.pm how to do this.  The question is.... how 
do we want this to look from the UI?