How to get the screen to split and set to projector

I have a Dell Latitude D820 with Microsoft XP Professional. Basically what I need to be able to figure out is how to have dual screens on the laptop with only one screen showing up through the projector. In court, we need to be able to have one side of the screen show up, with notes on the case, and the other side to be exhibits. Ideally we would like the computer to be able to function so the screens will be split in two and someone will be able to look at their notes and do things on one side, but also be able to bring up exhibits and pictures for the court to see on the other side. This way everyone will not be able to see the notes and just see exhibits, but the person on the computer would be able to see both.

 

Any help would be greatly appreciated.

 

Meggie