Originally Posted by ijgordon

I'm not sure what you mean by "multi-city" search in ExpertFlyer. As you may have figured out by now, there are two key modules for paid travel in ExpertFlyer, Flight Availability and Fare Information (ok, maybe seat maps too...) Flight Availability only shows you flight schedules and inventory/booking code availability. Fare Information shows actual fare basis codes and has fare rules / routing information, but only for a specific origin-destination city pair. Whether a particular fare allows a stopover is typically in the fare rules or routing information for that fare. So first you'd have to find a(n upgradeable) fare that allowed a stopover and had an "MPM" (maximum permitted mileage) greater than the routing you intended to fly. Then you would have to check Flight Availability for flights that had the appropriate fare class available.

The first part can be challenging because of all the different fare rules -- seasonality, day of week restrictions, advance purchase, minimum stay, etc. There can be five different "S" fares with different requirements. And if you're talking about international travel, it's exponentially more complicated than domestic.

I really think you're best off picking a few possible routings, getting the lowest available fare from AA.com, and then calling AA and asking what the lowest available upgradeable fare is for that same routing.