That MixMaster looks good and it's donationware.
But it will take a lot longer than the other to methods.
I think the easiest way right now is save the midi file and save to ABC.

1. Download Karakan https://sites.google.com/site/karakankaraoke/

2. Biab > Options > Preferences > OutputChords (see pic below)

3. Biab > File > Save Special > Save Song as ABC Notation

4. Drag ABC file into NotePad

5. Notepad > Edit > Replace > copy the characters you don't need
and paste in "Find What" and in "Replace With" leave blank to remove or add new character to replace with. If your chords have numbers in them find 7 replace with \7
6. Open Karakan > open the midi saved from Biab > Select Voice track > BB Chord Output.

7. Copy and paste the chords from notepad into Karakan > Play Karakan

8. Karakan menu > Karaoke > Save to MIDI file with Lyrics

Attached Files (Click to download or enlarge) (Only available when you are logged in)
BB-Chord-Output.png (25.58 KB, 129 downloads)
Notepad-ABC.png (64.48 KB, 129 downloads)
Notepad-ABC-2.png (76.17 KB, 129 downloads)
Notepad-ABC-3.png (46.98 KB, 129 downloads)
Notepad-ABC-4.png (71.63 KB, 130 downloads)