http://www.qatarliving.com/node/30531

Some info on that, including:

King Edshel said Church ...
I guess that you mean [PSD] Philippines School Doha. There is a mass every Thursdays around 7:00-8:30 PM and Fridays early in the morning 7:00-8:30 AM. They held it in the school itself, so it would be easy for you to find it and yeah ... it is behind LuLu

CharanSanitwong said There is a church (so ...
There is a church (so called) near City Centre. They have 2 masses every Friday morning.

Hope that helps and YIKES I didn't realise I was now living so close to a 'church service' that I now have no excuses!