yup, as has been said, you are only really limited by the available inputs into the card - mine will take RF, svideo or composite, which is handy, as I have a dvd player & vhs recorder plugged in as well as the cable TV.
When you connect the cable tv feed, your TV card will have a setup routine which will tune in the signal - bear in mind that the cable programs will appear as only one 'channel', you will still have to use the cable box remote control to switch between your subscribed programs.
- let us know how you get on