In my opinion, "no matter who" cannot operate as a pronoun. Also, while it is an expression that is often used, it is always part of a longer expression. The expressions in which it appears are, I think, generally adverbial phrases. It cannot replace
whoever..
But the fact is, bullies are bad no matter who they are!
http://www.zdnet.com/anchordesk/talk...ck_210990.html
No matter who steers, the wheels of justice turn
http://www.sptimes.com/2003/05/14/Co..._steers_.shtml
No matter who loses, his supporters will feel robbed. And no matter who is chosen, those who feel robbed will be right.
http://www.lollie.com/gallery/whowins.html
No Matter Who Wins an Election, You Still Lose
http://www.geocities.com/decriminali...om/voting.html
No Matter Who Sits In A Director's Chair It Needs To Be A Class Act
http://securities.stanford.edu/news-...10_Gettler.htm
It's my house, no matter who owns it
http://www.csmonitor.com/2003/0409/p15s01-lign.htm
Justice Will Lose No Matter Who Wins
http://www.griffnews.com/droleskey/001113.shtml