I've got a similar set-up I think,
I connect my scart socket on my VCR to the S-Video port and the line-in jack socket on my PCI TV-card on my computer.
I use a normal scart to S-video & stereo AV leads which you can get from Maplins or any high-street electronics shop.
When you connect it all up and hit play on the VCR you won't automatically see the footage on the computer scxreen. To view and capture the footage you need to use some software, I use Arcsoft Showbiz, which was bundled with my DVD writer I think, but you can use most editing software to capture from analogue sources, I found Showbiz the easiest and most robust thing to use.
I'm not sure what the other ports are that you mention, but you can definitely use a
Scart to S-video cable like this one to do the job.