CLI or programmatic way to return books?

Public terminals in our library allow patrons (despite signs telling them not to) to download ADE books.  That would be OK if they returned the books when they finished.  Since they don't, we'd like to be able to return all books after the library closes for the night.

Is there a command line switch  (/RETURNALL or some such) to digitaleditions.exe that would cause all borrowed books on the system to be returned?  Another way to achieve this?