Redirecting blog permalinks from Movable Type to Wordpress?

I recently reincarnated my blog, and even more recently brought over entries from other blogs into it. One of those blogs used to run Movable Type 3.2. As a result, the entries used to reside in /year/month/day/post_name.html style directories. Since that particular blog used to reside where Wordpress now resides, those posts now toss out a 404–WP uses /year/month/post-name/ instead. Is there a relatively painless way to convert the old, MT style permalinks to the current, WP-style? Or, would I be better off converting WP to the old Movable Type style instead? Thoughts, comments etc would be awesome. thanks if anyone can help; my google foo has turned up close, but not quite what I’m after.