Mouse movement across 2 screens

Hello,

First of all, best wishes for 2009,

I just installed a GForce 8400 GS graphics card to be able to use 2 screens.

I've installed all the drivers and there's no problem with screen management.

My problem is rather with the mouse. I have a 22' screen that is my main screen, and my 2nd screen is a 17'.

The position of my screens: the main one is in front of me and the 17' is to my left because I can't place it on the right.

When I want to move from one screen to the other with the mouse, there’s no problem, except that for my PC, my 17' screen is to the right, and I have to go through the right side of my 22' to access my screen that is on the left.

I'm trying my best to give as much information as possible, but it’s not obvious for this issue.

My question is as follows: how can I make my PC understand that the screen is on the left so that I can access it with the mouse from the left?

Thanks in advance to everyone

Configuration: ASUS P5GC-MX/I333 Motherboard 2Go DDR2 PCI Express Graphics Card GForce 8400GS Windows XP Pro Internet Explorer 7.0