macker, you are right, no one should rely on the forum like this if persons like yourselves kept commenting on something that they have no clue about. What British Embassy has to do with obtaining any kinds of visas in Qatar whatsoever? If you are citizen of let’s say India and you want visa to Germany, where would you go: to Indian embassy or to the relevant German institution responsible for visas to Germany? What a nonsense some people are saying.
Itsallnew, rather follow mircea's advice. First you have to be qualified to sponsor your family. Once you make sure that you are qualified, gather necessary documents and submit your application to the relevant Qatari authorities. But my advice, first, check this matter with your company, as in any case you have to have a status of your visa as “Family status”. Usually companies either help you with this matters or even provide such service to their employees for free. Ask your company first.