Choose which audio channel audio comes from

i have surround sound on my sound card, 7.1 but i only have 5.1 speakers and was wondering was it possible to take songbird and push the audio out of the one channel i don't use into like a set of headphones or something. ive always wanted to have my music comeout of dedicated speakers or something. if you catch my drift is there any functionality in songbird or planned or an addon?