Right click -> PropertiesYou need to add the track number to the ID3 tags, which I know for sure you can do in iTunes, not so sure about Foobar.
The ID3 tag editing in Foobar is beyond amazing. Makes editing songs a breeze even if they don't have proper tags to begin with as long as the files have names.
Edit: this thread is a wrap. Enzo, where you at?