agree with pwarren - I do this all the time when I have a melody and want to create chords to go with it. I don't always like what it comes up with and will sometimes have to go back and manually change things, but it's a good start.

the ideal way to do this would be to create a midi file of the melody and the 3rd above the melody. that would create the chord structure for BIAB to identify for you. if you don't choose the 3rd, then it could either be major or minor and BIAB will choose whichever it "thinks" is best for the chord progression.