There is this neat little search option here in QL upper right hand corner below your name where you can check past posts for your answers before reposting a very popular question.
Just type in cargo companies .

Here ya go. Best wishes
http://www.qatarliving.com/search?cx=008937172676595728955%3A066rihafv68...

Lots of links, to help you.
Also try this yellow pages link.

http://www.qatcom.com/listings/qatar-search/cargo-services-air