Hello,
There would be no "easy way" to do that, if you are accessing file server via RMS it will have to use RMS generated link for it.
You cant really bypass all of the system that makes access possible, and get direct link to file system. and since at least right now RMS does not have feature like custom URL generation, I don't really have another workaround except using some third party service that lets you create custom URLs to redirect to endpoint that you want.
That however might be a good suggestion for a feature to be added to RMS in the future.
Best regards,
VidasKac