Welcome to Deezire Online Forums and the C&C Modding Community
Unfortunately my site is down currently, so I can't direct you there.
You should download XCC Mixer and XCC Mix Editor from
http://xccu.sourceforge.net
I'm going to bed now, but I bet someone will answer your questions.
Anyway I'll be back sometime tomorrow.
P.S. you should have posted this in the
Red Alert 2 & Yuri's Revenge Editing forum, not in this forum.