That's a ATI/AMD card, I'll see if I can find online how to do it. Have not dealt with them in a while.
Well there seems to be a LOT of people having trouble figuring it out LOL Not a fan of ATI control panel for this reason, I did find a site with a lot of info to try and should help you get it set up. A bit of reading but it should help you out some.
How to Set Up Multiple Monitors - Puget Custom Computers