How do I bypass KMixer in Windows XP

Guys;

I have searched the threads and still have been unable to determine how I can set up my external USB Dac to receive a USB feed out of Windows XP WITHOUT the signal passing thru KMixer.

I'm struggling to figure out if there's a fairly easy way to do this, or if a move to Vista- or a MAC- is the way to proceed.

Your direction is appreciated!