That S-video is not too put stuff in the computer. Its an S-video out, so you can hook your computer up to a TV if you wanted to watcha movie on your TV that is saved on your computer. There is no way you can go against traffic through the video card and onto your computer.
Anyway, if you want to hook up an analog camcorder to a digital computer. In other words convert that analog signel to a digital signal, there are special connectors you can buy, you might have had one come with your camcordor. Otherwise you can buy them. They will plug into either USB or Firewire, if its not one of those, its probably not for sending video to the computer, you also have to have the right software on your computer, like Microsoft Movie maker, best for starters.
Good luck.