train to cdg from Cosne-sur-loire

Go to this site and put in your dates. It will show schedule and a little note "not for sale yet" and instructions if you want an email when they will go on sale. https://en.oui.sncf/en/tgv

Trains go to Bercy station, about 1/2 mile walk from Gare de Lyon where you have to take an RER train to either Les Halles or Gare du Nord and change to the RER B train to the airport.

An alternative would be to take the No 14 Metro from Bercy to Chatelet-Les Halles and take a long underground walk to the RER platforms and get the B train to the airport. Lifts/escalators both ends No 14 line and also down to the RER platforms.

Additional option for getting from Gare de Lyon to CDG is Le Bus Direct, Line 4: www.lebusdirect.com.