The most probably choice for a WVE to MPG conversion seems to be the export of Wondershare Video Editor projects (*.wve) as MPGs. If you looking for this conversion, then you can do that in the program using the default export function. Wondershare also offers trial version, so it may be worthwhile to check the program if you are attempting this conversion.
Other WVE to MPG conversion doesn't seem to be possible. DIVX WVE is just some sort of data file used during the actual DIVX conversion and it probably does not contain the actual video.