There's a set of books (consisting of about ten volumes) titled Roster of Confederate Graves by the Georgia UDC that lists all known grave locations of Confederate soldiers/veterans from GA who are buried both in Georgia and outside of GA. From what I understand, as additional grave locations of soldiers/veterans not already listed are discovered, their names are being added to a supplemental volume. I know this set of books is available at the main library in Atlanta and may also be available in the libraries of other larger cities in GA. If you don't live near one of the libraries having them, try calling the Atlanta Library and see if they will check to see if you ancestor is listed in one of the volumes. Good Luck!