When you have created a soloist track in BIAB that is CLOSE to what you want, first render it to .wav or .mp3, then import it to your DAW. Cut/Paste to suit and use the segments as needed.
Yep....I've done that from the beginning of using BIAB. (about 6 years ago)
This is a great program with lots of opportunity left to one's song writing imagination.
I feel that approach was incumbent of me rather than just using defaults.
If I were asked, I'd recommend all BIAB users use that approach.
I only have (5) BIAB songs online but I've had as many as (8) separate lead axe/keys tracks that play all the way through the song then I import all .wav into my DAW (Sonar X3)
Then the time vampire process begins.....split all tracks into musical phrases, whether 2/4/8 bars and totally re-arrange them within the song to my liking.
All lead axe tracks on my songs are an re-arrangement of segments from ALL the tracks that I'd imported.
I've certainly confused myself more that once while moving things around so much.
Lots of culling in the process too.
Hope your demo works out to your liking....did I mention it can be a 'time vampire'?

But....that's just me.....carry on.