Although I understand what Daiwai means (sometimes people think i'm rude because i say it as it is and humans are sensitive by nature) but we all know that in Qatar laws and things change fast and sometimes even the people working at the trafic dept will not know the answer (from experience) so the website would be the last place i would check for anythingt new happening. I have been told by some colleagues who drive in Qatar with a valid international license that it had become unlawful to do so. So I would follow canarybird's advice or my own advice and go to the trafic dept or to the MOI who will help you with this issue, but don't give up quickly, get something written

Cheers