Multiple Sound Cards in Traktor LE 3.3

Is it possible to set multiple sound cards in Traktor LE 3.3? I just purchased a VCI-100 and a Behringer FCA202 sound card.

I need to output the audio via optical out (home stereo only has optical in), so I'm using my MacBook Pro's internal card for the 1/2 master out.

For previewing with my headphones, I'd like to set the cueing output to the FCA202 (or any other sound card that would work).

I heard that there's a solution for that on the Mac, but am unable to find any info on this on the web.

Here's my setup diagram.

The VCI 100 seems like a lot of fun, but right now I just can't use it . Any ideas?

I think you should be able to use the "Audio MIDI Setup" utility to create an "Aggregate Audio Device" out of two or more of your interfaces. I've never done it, but I'm sure someone else here can explain it in detail, or Google "aggregate audio device OS X" and I'm sure there will be examples.

The idea is that you'll create a virtual audio interface that has more outputs than any of your individual interfaces. Then, you'll use the virtual interface inside Traktor, and if you map the real stuff onto the virtual stuff correctly then all the sounds will go to the right places.

Hope this helps-