Dunno about CO, but AA permits car seats in the middle section of F and J on widebodies - and in any non-aisle middle section coach seat on widebodies:
May also be seated in any of the following:
any non-aisle Coach Class seat of the center section of a wide-body aircraft
any seat in the center section of First Class on wide body aircraft
any seat in the center section of Business Class
I'd definitely call CO beforehand - so you know the correct answer in case an FA objects. When my kids were in their car seats, I had success in very politely convincing AA SkyDragons to check their manual when I knew I was right and they were incorrect about where the car seats were permitted.