Emu XL-7 & MP-7 User's Group

Hey Just purchased the px-7, How do I get it to control my Tr Rack, 
sending midi msg etc, The only way I,ve found to do it so far it to 
send a prog chg. Any help would be apreciated also, when how do you 
program mutes at the start of a song, they wont rec for the life of 
me. Sorry if my questions seem juvenile I am a former software user. 
Thanks.