Just to make sure that you are aware, but the lower case "or" is treated normally and its only the upper case "OR" which is treated like specially. Google works the same way.
So if this is being built into a built in report, then you can just use the lower case.
If its an then you would need to train your users.
I have answered this question as a comment because I'm not sure if my answer solves your issue. If it does solve it, you can answer in the answer box to close out this question.