HDTV modulator

HDTV computer cards I've come across don't support encrypted channels. My cable provider (like all others in Canada) uses only encrypted QAM for HDTV and DTV in general, and one has to use their boxes with DVI or component outputs. If I want to watch it on the computer, I need to modulate such an output to ATSC or unencrypted QAM to feed into my HDTV card (preferrably with the sound as well). I don't have an HDTV and prefer to use the PC anyways, as it saves space and also serves as a PVR.
All modulators I've seen are S500+ and don't seem to support inputs like the DVI or component directly. Is there any more DIY solution, putting together several things to get this to work? Or is there possibly a software solution, given that the card does a lot in software anyway (it's a DViCO FusionHDTV5 Gold)?