SansaRocker,
Terribly sorry for not seeing this sooner - no matter what you do, it isn't going to work.
I don't blame anyone else for not picking up on this, but your device doesn't seem to support mpegplayer (the reason it is missing from the manual for your device). In the likely event that this isn't an oversight, nothing you attempt to do is going to play an mpeg file on this device, I am sorry.
[Saint]