Catalyst Control Centre is like Nvidia Control Panel. It's just software that lets you adjust your video driver behaviour - such as adjusting color, aspect ratio, custom resolutions, game profiles, 3D settings, etc. To display games in 4:3 on a display of a different ratio, you need either a connection that's not VGA (DVI, HDMI, or DP/Mini-DP). Open up CCC, and at the left hand side, expand "My Digital Flat Panels" by clicking on it. then click "Properties (Digital Flat-Panel)" There, you shodul see the option s for Scaling. Check the "enable GPU scaling" box, and select "Maintain Aspect Ratio"
Now, when you run a game that uses any aspect ratio other than your monitors' default, it'll scale properly, and use pillarboxing or letterboxing to fill in the rest.
What is your specific problem? Trying to run 4:3 game on a widescreen display, by the sounds of it. I do believe running 4:3 games in a window will leave their aspect ratio intact.