<human>: Can you give me a shortened version of the text?

Didn't hear anything from r/audioengineering... probably too much of a n00b question there.  Maybe here?  :) Please forgive and hopefully redirect me if I'm not posting in the appropriate subreddit.  

I have put together some background audio tracks for an event in ACID Pro.  As they are 5.1, I've exported each of the projects as ac3.  I have no particular need for video, but it might be nice to have the name of the track playing.  The catch: I need to play the files from a USB flash drive on a DivX Ultra capable DVD player.

I've tried a lot of free utilities (virtualdub, DivX-MuxGUI, AVI-MuxGUI...) and trials of commercial utilities (Premiere, Vegas Studio HD) but I keep ending up with vague error messages, applications that just don't open ac3 files, or applications that don't like MY ac3 files.  When I finally got some AVI video with my surround audio, DivX Converter Plus started dying partway through conversion with "Divx Transcode Engine Module has stopped working".  ಠ\_ಠ

So.  Before I go down the rabbit hole of troubleshooting every media conversion application known to man, I thought I might ask folks who know.  What's the most straightforward way to accomplish my goal?
<bot>: Audio newb has AC3 audio that needs conversion to DivX, with no real regard for any video content.  What's the easiest or most straightforward method?