This has nothing to do with map making.
hi my name is ben and i'll be your guest explainor for the day, thank you
direct conversion is not possible; midi isn't audio, it's more like a sheet of music for a player piano, and as a result sounds different on different hardware.
the only thing to do in this case is to re-record the music; you could set winamp to use a disk writer output plugin and play the midi file into a wav file, or you could be a cool guy and run a patch cable from your headphone port to your microphone port and record the whole thing with windows sound recorder (i guess that's somewhere around eighty points)