First, you really need to search for threads that address your request! Such as:
http://www.eq2interface.com/forums/s...ght=mp3+player
Second, No need for one, since EQ2 runs well windowed. You can use MSoft's media player or any other mp3 player easily outside of eq2. Just window mode if your keyboard does not have mp3 controls built in. Mine does, so I que up my playlist outside of eq2. Run the mp3 player and then launch the game. My keyboard allows me to skip, repeat, or anything i need to do while listening to the music. (Just remember to "mute" EQ2 sounds in game via the sound settings.)