Ikar: Try the search engine on www.staralliance.com

Anyway, figuring out most regular routings is usually not rocket science.

If there is no direct flight from your airport in the US to the desired destination in Europe, you can either check which US *A hubs there are direct *A flights to from the destination and connect in the US or which *A hubs in Europe (if any) there are flight to from your airport in the US and connect in Europe.
If there are no *A TATL flight from either your airport or the destination airport, the you obviously have to double connect, and pick a hub both in the US and in Europe.