You won't be able to fit more than one AA (14x50mm) is the space of a C (25x50mm). Multiple AAA's fit in a C, and many lights use 3 AAA's in series in a battery carrier, but I've never seen such a carrier sold alone. AA->C adapters are available (Sanyo's giving them away with the purchase of Eneloops), but that probably won't help you.