The "norm" for cinc (or RCA) cable is red = left audio channel, white for right audio (although this is far from gospel and sometimes is the other way 'round) and yellow for video. So the yellow socket should be analogue video.

If your camcorder has a yellow socket marked as "video in" then it should work.

I suspect (from your description) that the camcorder has a small av socket (looks like a 3.5mm mini headphone socket) which is normally only for the camcorder to output to a television or suchlike. Unless it can be switched (in/out) then it will only be one-way ie: out.

You can't plug analogue video into a digital input without converting it first.

So, it sounds like you'll have to look for another solution. Either a camcorder which will accept video-in, a portable video recorder (expensive) or a laptop with analogue video in (also expensive).