wow you actually used winmx in this day and age? Better not mention how much people take the piss out of winmx users then
You can convert complete part files to emule pretty easy, check the sticky about ftp2donkey. You need the ed2k link and the temporary files have to be complete (ie. it puts things into order and then renames it to the correct filename, or downloads directly into a file... like torrent or ftp does for the latter or emule does for the former).
You need the hash that it should be though and it will drop any chunks not 8mb so it may step back a bit.
Can't imagine why you'd be downloading anything on winmx you can get on emule though.