ahh, i've a trouble just like this once. i want to play some games while my friend wants to watch movie. and my tv is connected via hdmi to my pc because i use my tv as a 2nd screen most of the time but my tv also has it's own speakers.
the way i did it is using Media Player Classic to stream audio directly to HDMI via AMD HDMI Output and my game application to stream via default soundcard(Onkyo SE-90 in my case).
the only thing i need to do is open the option tab on the Media Player Classic menu wich is View>Options.
in the options menu dropdown look for Playback>Output. there on the bottom there's Audio Renderer dropdown menu.
now you need to have the HDMI cable hooked up on the PC and working properly to make it available at the...