That is exactly what we would do - AA & LA from ORD to GIG and the IB from BCN-ORD. Getting to GIG will be a pain (double connection) but the flight from BCN is a direct flight (at least it is in 2006!).

And, it is correct that only the mileage between the origin and destination are counted. That's the way they calculated our OW100F award for July 2007 where we are starting our cruise in CPH and ending in ARN.