hmm... my pinoy colleague sends money back home using western union I believe... perhaps you can check... and since they're money exchanger, and USD-QAR exchange rate is fixed, you don't have to worry about any losses I guess... (except for fluctuating QAR-SGD rates)

hope this helps..

otherwise maybe you can try PayPal, but I'm not sure how to top up your PayPal account via a Qatari bank...

good luck~