Most of the audio applications in Windows can select the output channel. For those who do not know how, there are sound mapper. It can be controlled so: right click on the speaker icon in the system tray — "playback Device" is assigned the default device. There is no other way.
Synchronously in the two zvukovojj the sound can not go by definition. They occurs work with a slightly different frequency. Needed an app that would on the fly did a little resampling implementation. In Linux this makes it a simple utility jack_diplomat, for example, but it's connected to jackd. In Windows, this can probably do most daws, especially using rewire, but this is shooting from a gun on sparrows.