Macbook multi-channel audio routing

[jonahmo]

I'm trying to output two different mixes of a live session, one going to the outboard speakers, another going into a video program (VDMX5). The only way I've figured out to output two different mixes is by using my interface (Focusrite Thunderbolt), so I've got the main output going out on channels 1-2 and the other mix going out on 3-4. I want the mix in 3-4 to go into VDMX5. I have Soundflower installed - not sure if/how that will help me. Any suggestions much appreciated. Thanks!