Not to be the bearer of bad news... You can try running drakxconf to set the refresh frequency, but if the card is not detected properly (try lspci at a command prompt) there's not a whole lot you can do besides getting a new video card.
If you're really intent on using THAT card, you can check out the information on http://www.xfree86.org
and see if they have a new version that will support that card.
As far as a steb-by-step, that problem is too ambiguous for simplification. Get out on http://www.google.com/linux
and see what others have said. You can also try hardware compatibility sites like http://lhd.datapower.com
and the like to see what other users have done.