EX2 Mirror to USB Backup Option

I’m a simple man with simple needs. In a woman all I want is a brilliant, supermodel brewery heiress. 

For a NAS drive, all I want is the ability to connect an external USB drive that can be used to mirror the contents of my EX2, with automatic recurrence intervals daily, weekly, etc.

I’m a simple man.

Oh, and the external drive should be invisible to the public.