Optimal method to store XPath definitions.

Question

I know how to use XPath, but often wondered what is the optimal way to store then during runtime. In the past i've split them up into individual bits, stored them as character strings, and one or two other ways.

Now I have a configuration file with bundles of them, like twisted knots, and am now looking for the optimal way to store them once they are loaded from configuration. DB is not an option.

Thanks. Bob.