You'd have to make it use FIDs for file storage, and understand the static database format (all this is in the emptool sources) but if you added files with the 'type' field set to something apart from 'tune' or 'playlist' (eg, 'file'?) then the player would ignore them & you could deal with them as you saw fit.

In theory, the easiest way to do it would be to modify emptool (or the java version) to be able to download files from the empeg, and to support files which weren't ".mp3" (no tags, etc) - then you don't have to write a while new app.

Hugo