If I understand you correctly, you have an award ticket on DL from LAX-ATL and a revenue ticket on AF from ATL-CDG-FCO, and you want AF to reaccommodate you in advance on a more direct flight (e.g. one connection instead of two) because of a prospective oversell situation. Sorry, but that's not going to happen.
First, AF is not going to help you get all the way from LAX to FCO when they are only obligated to transport you from ATL even if there were nonstop options from LAX, which there are not on any carrier much less AF (in theory, the most you could accomplish is to eliminate one stop by making a single connection either at an American or European hub). Second, all airlines are almost universally unwilling to entertain a voluntary bump in advance of the flight.
The best you can hope to do if you arrive at ATL to find your AF flight to CDG oversold and AF in need of volunteers is to ask them to rebook you on DL's nonstop ATL-FCO service (DL #70).
[This message has been edited by cAAl (edited 08-01-2003).]