The church has a Dell Laptop with an extension plugged into the back.  That extension has a VGA port which outputs to another box that then outputs to a TV.  

They bought another external monitor and plugged it in the VGA out on the side of the laptop.  However the laptop only shows 2 monitors and the monitor they bought says to hit any key to bring it out of power saving mode.   Of course nothing happens when you press a key or move the mouse because that monitor evidently isn't recognized.

The VGA port on the side of the computer must have been inactivated by the extension on the back.  

Can they get a splitter of some sort to plug into the VGA extension so they can then see the new external monitor or is there software that would recognize the VGA out on the side of the laptop.

The computer is running Windows XP.    They have everything working just fine with XP and I imagine they'd be reluctant to spend a lot of money for another computer just to run a 3rd monitor.