Hiding some custom modules from the module browser and not others

We have one or two custom modules that we have created, and we ideally don't want them to be available in the AWE Designer module browser, but we do need them to be accessible from the Matlab API  (because we use these custom modules as components in building a more complex custom module, and we do need this more complex custom module to be available in the AWE Designer module browser). Currently we just have these custom modules in a sub-directory of our third-party directory in the module browser. Is there any way we can make these modules hidden from the designer GUI completely, while still making them accessible from the Matlab API?

Many thanks,
Jake