I'm trying to make a recording with a quality MIDI solo instrument track and Real Tracks for the rest. If I use the default MIDI synth, it works well. I select File...Save Special...Render as AIFF and I get a recording that has both the Real Tracks and the synth track I made as "Melody".

But I'd like to have the Melody played by Kontakt or some other software synth. I am able to connect Kontakt through the IAC bus and it sounds great when I listen on my computer. But when I record as above, I don't get the Kontakt synth. How might I be able to do that? Thanks.