Ahh, gotcha. That'll be SVHS out.
I had a little dongle when I bought my card (Geforce 3 Ti200, OEM) which plugs in to the SVHS socket and provides a female phono (RGB yellow) on the other end.
Did you not get one of these with the card?
SVHS cables are not cheap!
How about this
one? Price isn't as bad as I thought