Assuming "oja" is being used instead of "ojo" (eye) then you could form a phrase like "eye to God".  But ojala is from the arabic "inshalla", which as the OP states, means "God willing".

Did you hear this from people in Spain?  Or people in other Spanish-speaking countries?  In Spain it is very well known that this is an arabic phrase, as are many other arabic phrases and words that are in Spanish.

Here's a handful of other examples...