Thanks for the guidance. It is really helpful. What I am trying to do is use a MIDI melody track in RB to generate my accompanyment, then retain the MIDI track melody as a decent sounding instrument. So...

Based on the advice you guys are giving me, sounds like this might do what I want...

1. Load the melody MIDI track into RB.
2. Generate the deisred accompanyment tracks
3. Assign a VST plug-in to the original MIDI melody track to get a decent sounding melody. Also may want to convert to WAV for post processing.

Does this sound right?