OK. Consider me squelched
.
You can do this from a tiny little popup form with a single command button on it. The button can be very small and have an X on it like the report's close button. The form can be stripped of Max/min and close buttons, record selectors, control box and nav buttons and be non-resizeable. The button invokes the DoCmd.close for the report.
The report's close button is disabled. The tiny form is opened from the on Open event of the report and closed from the on Close event.
This method can still be defeated if keyboard shortcuts are allowed.