23 year veteran with American Airlines reservations... Executive Platinum, 5 Star, ConKey I can teach you...
You will have credit to use the ticket as it's routed unless you no showed the flight. No show meaning... the flight took off and you did not cancel the reservation before it happened.
The best thing to do is to call AA Reservations at 800-433-7300... so that the rules of the ticket can be researched. If you had 2 one way tickets to create a round trip, then a valid ticket could be used to another destination.
You will need the AA ticket number.. Our ticket numbers start with 001.
Hope this helps you.