Dual Soundcard Input Routing

I run two Soundcards - A Sound Blaster Audigy 2 ZS Platinum for gaming and a Chaintech AV-710 for music and connecting to my Headphone Amplifier.

My LCD has Composite Input, so I connect my PS2 to it and then connect the Audio Inputs to the front inputs on my A2ZS Platinum. It works flawlessly with one minor point: The sound is then output through the Audigy 2. It's not a major issue, but it would be convienient if I could route that input to play through the AV-710. All my testing suggests that this is impossible, but I was curious to know if anyone here had tried something similar and if it was at all possible.

Jam it back in, in the dark.