Use a multi-city search on AA. If the layover meets the maximum layover window, the site should price it as a single leg, not multiple segments, even if that option wasn't coming up on the simple search. (as in, the cost difference between a 2hr and 20hr layover should be small).

Also, consider Google Flights, that can also force itineraries to show on aa.com that don't come up on AA's search engine.