Hooking Xbox up to PC speakers

I'm trying to get my Xbox to run through my computer speakers.

I have this wire (not with me so I can't test it):

http://jetmall.net/index.asp?PageAction=VIEWPROD&ProdID=345

Can I hook this up to the xbox through this:

http://images.pcworld.com/news/graphics/131322-xbox_cable1_350.jpg

And hook up the cable to my speakers' mic input (and turn up the mic volume corresponding)? Will that work?