You can hi-lite the melody notes in the piano roll, cut and paste to channels 11-16. Be sure to use "re-channel" option after pasting them in. Hi-lite, r-click, rechannel events/data etc . . . all done in piano roll.

Or:

Save Biab song as type 1 midi file. Open in RB or midi sequencer, hi-lite melody part(s), cut and paste to the next available open non-Biab used tracks. Rechannel, save as midi type 1, import midi back into Biab for further edits etc . . .

Trax