Could someone please tell me if there is a train from CDG to Strasbourg?
Yes, there are several direct TGVs per day right from the station at the airport.
Check times and prices on www.oui.sncf or www.trainline.eu. Be sure to enter CDG not "Paris" as your starting point in the search engine.
Tip. On either of those web sites, when entering your departure point, type "Pari" and then pause. A list of possible stations is shown and toy can select the airport.