How to define a 2nd Inbox folder in Finder?

I use the Inbox folder in finder a lot to move documents produced by other apps into DEVONthink.

For scanning I use an external app (VueScan). I want to point VueScan’s output directory at a DEVONthink Inbox folder in which (through a DEVONthink rule) all image files are automatically converted into PDFs.

How can I set this 2nd Inbox up?