Autoselect destination folder in DownThemAll 2

Question

I read somewhere that you could set up filters in DownThemAll 2 Firefox extension, so that some files would be automatically sent to folder A, and other files to folder B. I've been poking around in the settings and I just can't find out how.

Just to be clear, I'm looking for a way to have all .mp3 be saved to the Music folder, and all .doc be saved to the Documents folder without having to select the right folders every time (only with more customization, of course). I used to achieve this with another extension (which I can't remember the name), but it doesn't support Firefox 4 yet.