If so, it's actually a video out port. You should have Function key and an F key combination that switches to use that port. These usually have blue icons that resemble an PC screen. Look at F-7, 8, and 9 and one of these plus the function key in lower left might do it.
My Sony 40inch LCD TV has a serial port which is labeled PC in. I have connected the Laptop to the TV via a Serial Cable. How do I set up the TV and the Laptop to watch video on the TV instead of the Laptop monitor. I am running Windows XP Professional on the Laptop.