I work with a 3rd party framework that uses resource files to handle multi-lingual issues.
They arrange things a different way.
All the resource files have the exact same name. The "default" resource file is in the regular resources directory, and each language is in a language sub-directory below it. The sub-directory name is the language/culture code, i.e., ca-ES, da, de, es, es-ES, fr, hr, it, and so forth.
Hope that helps!
If this answered your question, be sure to mark it as the answer. That way, everybody after you will know it's the answer also!