Output through d-coax, in native file resolution

I have a variety of music files in 24 bit and >44khz. I am wanting to pass that through to my DAC in the files native format.

Running Vista/54 on an ASUS m3n-deluxe using its digital out. Using foobar. realtek HD Audio manager/driver.

In the real tek you set the output resolution to what you like. Ie its now fixed where I'd like it variable and dependant upon the file to determine the number of bits and sampling frequency.

Ideas?