inserting midi command somewhere to change soft synth program/sound mid-song

EDIT: I'm inserting an edit here to be concise: I know how to use Envelopes to insert MIDI automated events that are easily controlled through the Sonar application itself like panning and even effect considerations, but how can I tell it to change the .prog a soft synth is playing i.e. change instrument (or is that impossible... you'd think not!) without having just a whole other duplicate soft synth open sitting on a different instrument setting? I originally typed: I know how to enter some automation like mixer levels, pan, etc. to happen automatically in midi mid-song, but how can I tell a single track and/or soft synth like Dimension, Rapture, or Session Drummer to change to a different .wav or .prog (at different times not simultaneously)instead of having lots of the same soft synth open on different tracks to the same end (that wasting RAM)? This is probably simple but has evaded me. This and I'm going to also see if Sonar 8 Studio can, I guess the proper term is "side chain" to automatically either compress or dynamically volume fluctuate as to blend track together in final mix beyond simple slider control and manual compressor settings etc. Sidechaining, and separate issue: big one, using one track or at least on synth to play different sounds at different times without just opening multiples an stacking. If you can help with these two things I'm well on my way to a better finished product THANK YOU :) Jeff Tampa, FL, US