Region Encode BluRay issues

So here is my problem. I burned copies of my film for festivals. A couple of european countries have asked permission to play them. I made a couple of copies and sent them out. Now I have one come back and state that it is the wrong region. I thought BluRay was universal. So upon research I found out that there are three regional permissions applied to BluRay. No problem, however I can't figure out how to change the regional settings within Encore's encoding process. How would I go about this in Encore?

Thank you, Jessica. I believe that it is a Mac issue. I am transferring my footage to PC to see if that will solve the dilema . The regional option in the build tab isn't in my Mac version of Encore CS5.