The most probably choice for a WVE to MP3 conversion seems to be the export of Wondershare Video Editor projects (*.wve) as MP3s, which will only export the audio track not the whole video. 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.
There is also WVE projects from another multimedia editor called WaveEditor from PowerDirector. These projects are generally exported to audio formats, including the MP3.
Other WVE to MP3 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.