True 5.1 Surround using Digital I/O upgrade?

Hello all,

I'm trying to connect my Xbox 360 into my computer's 5.1 Speaker setup
through my SB Live! 24-Bit external card, and was wondering if the
additional Digital I/O Module would solve this problem.

The 360 uses Optical S/PDIF as its output source for surround sound and
was wondering if using the "Optical In" from the Digital I/O would
retain 5.1 surround if I connected it through my SB external card.

I'm skeptical since it looks like the Digital I/O uses a regular
coaxial cable to connect to the soundcard, but I haven't seen it in
person so I don't know if that is how it works.

Any help in figuring this out would be appreciated!!

Chris