I finally succeeded in doing this. I had been on the right track, just not careful enough. For one or a few tunes, it's definitely not worth the trouble, but I did 130 in one fell batch.

I'd be happy to go into greater detail if anyone wants to try it, but the first and most critical step is to make sure your word-processor list is absolutely uniform-- i.e. if a comma means end-of-stanza in one song, it must mean the same in every song, and it can't mean anything else anywhere. And each song must be the bare-bones core progression; you can add the subtle details when you get it into the editor.