[chroniX]

I have an X-Fi Elite Pro sound card (I'm not using the i/o external breakout box). I've already connected my 360 to my PC monitor but would like to get sound from my headphones. I was wondering if I could connect the RCA/composite (red-white) audio cables to my sound card or if I would need a RCA to 3.5mm adapter?
 
Here's a picture of the jacks on the sound card: http://images10.newegg.com/NeweggImage/productimage/29-102-191-01.jpg
 
Any help would be appreciated, thanks!