Originally Posted by dvs7310

Just turn it into a stopover if you wouldn't use the final segment for anything else (like DOH-AUH or DOH-DXB for example).

In theory you can end the ticket anywhere in the middle east, but depends on what your earlier itinerary was. If you ever had a stopover in DOH before, then QF can't do it. If you haven't then, you can at least make it a stopover now and just leave the last DOH-CAI segment unused.

If you won't have check in luggage, then you can just walk out of the airport in DOH and do as you wish, even on your existing ticket, but if you do have check in luggage, then QR will insist it is checked through, they don't short check. They may or may not give you difficulty about leaving DOH the same day on a different QR flight however. Best to use another airline to leave DOH if you go this route.

If all else fails I'd change it to xxx-DOH-AUH or DXB, they are cheaper and faster to get back to DOH from than CAI.