Is the run time also on the USB?
If the Runtime is run from the USB Flash drive, the path would be local and easy to do.
If the Runtime is installed and run on a variety of computers, it becomes more difficult. Especially if the users may be inexperienced.
File Plugins would allow this - this is a list of Filemaker File Manipulation Plugins
No runtime is on drive, i just want a backup copy on usb.