This question has been addressed at length in other threads. Bottom line: you're entitled to get in if you're departing on any qualifying flight on the day you want to get in. It does not have to be at the departure airport of that qualifying flight. It can be at the departure airport of a flight that connects to it, its arrival airport, or anywhere else, as long as you want to get in on that day.

Two caveats:

1. Not all agents understand this fully, since nearly all the requests for access come from people who are departing from that airport. It may help to carry a copy of the rules.

2. Many US-CDG flights arrive the day after they leave. You therefore do not have access privileges on arrival, since it's not the day of departure. Some staff members will let you in anyhow.

Finally, I don't know what the logistics of getting to the AC after arrival are, or if there are airport/government regulations that override the oneWorld access rules. Either of these could make it impossible no matter what AA would otherwise let you do.