1. Have the certificate translated. Go to any of the translation offices listed here:
http://www.qatcom.com/listings/qatar-search/translation-services
2. Once translated, bring the document (original file with translation) to your embassy and have it authenticated.
3. Bring document to the Ministry of Foreign Affairs and have it authenticated again.

Process should be in this order. You can't skip any of the steps. And make sure that you don't mess up the documents after being translated. They have a way of folding the edges and stapling them all together to show the stamp on all pages.