De-link the f8(Play) button to itunes?

Hello, I've been using itunes for a while and it just messed my entire music library up! I've found something that is more Winamp style for me named "Cog". Now my problem is that I want to control it with the F7, F8, F9 keys which are the rewind, play and forward keys, but when pressing any of them it works both on itunes and cog player. How can I disable the Itunes link to it? I want it to control only Cog player. Hope you understand me, english is not my native language...