Hi John,

I'd say your best bet would be to record the guitar as audio, have Band-in-a-Box transcribe it, then play the transcribed MIDI notes back with a bass patch.

There's a great tutorial on using the transcriptions feature here:

http://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=481276&an=

Thanks
Kent
PG Music