Do you write Perl? Familiar with Perl's DBI and Mysql libraries? Writing your own converter is a big project. I am not familiar with the details of either system. But I have written forum converters from scratch. One way to do a forum conversion, from Forum A to Forum C, where an A to B converter exists, is to modify the A to B converter so it targets C instead of B.
Doing the whole thing from the ground up (in the forum case, which I did) took almost me a week. Perhaps a star programmer could have done it in a day. If you are getting paid by the hour, a week is better than a day.