I don't think that suggestion will yield a digital path. The graphics cards that I have seen with VIVO (video in, video out) have analogue audio inputs.
If a true digital signal path is a must-have, you need to do one of two things:
1. Check your sound card to see if it has a digital audio input capability (many have an SP/DIF output, but few have such an input).
2. Buy a digital audio card for your computer. Several are available - both internal as well as external (PCMCIA) devices - check music magazines for info. In the UK Computer Music is a good source.
I would say that unless a pure digital path is a must for some reason, go with the analogue alternative, which your sound card should already provide.