Hi Jerry,
You said: "I can access and save it for any track in the midi file, but accessing it to change the lead voice has me stumped."
I'm not quite sure if I understand your question correctly. I just experimented with one of my midi files & put in program change 115 at the beginning of the lead track. The lead track played using the steeldrum as it's instrument. In order to change it to another instrument, you have to insert the corresponding instrument program change number into the track that you are trying to access.
Wally