I posted a script on how to import iTunes playlists, which basically converts an exported list into a Subsonic/Madsonic format.
The link is here:
http://forum.madsonic.org/viewtopic.php?f=29&t=553 However the site is down for updates at the moment, so you won't be able to access it.
Once the site is back up, you can follow the scripts, configure them to match your configuration and it should work fine.