he OnWorkbookOpen property provides facilities for trapping an event fired by
Excel when opening a workbook. Consider the following code.
The output of the signature() method indicates that the event handler should
accept one argument. We define such event handler and pass it into the bind
method. Consequently, opening a new workbook directs output to the
ControlShell as show below.
The "workbook opened" event is fired when a workbook from the hard drive is
opened. A newly created (in application) workbook does not fire this event.