this is not a standard that can be set without the help of a server, as rock mentioned. for colours it was relatively easy to hack the IRC protocol into accepting control codes in messages. in this case, mIRC will never know if the server passed the message onto the channel.. think about it, how would mIRC know if the message got through? It's like yelling into a dark cave and getting no reply and trying to figure out a way you can guarantee someone inside the cave heard you by yourself, without a reply from someone inside the cave