Jaargh,
Qatar's A330's (-200 and -300's) can be found servicing EVERY route on the network either routinely as timetabled, or occassionally as back-up. It's probably easier for us to list the routes that definitely do NOT use the A330 and, for the moment, these are as follows:
TXL / JFK / IAH / MEL / IAD / NBO / MCT / SAH
Some of the routes on which the A320 series predominates, but which occassionally are served by the 330 (and even 777 and 346), are:
NBO / SEZ / COK / ATH / GOI / AMQ / SAH / DAR / IKA / MCT / AUH / most other India routes except BOM and DEL.