Microsoft Excel - Trigger code if comment added, deleted or edited

I need to trigger code to to run if a comment is added, deleted, or edited. Unfortunately, comments are not recognised in the worksheet change event. Excel must have a way of recognising comments being added, deleted, or edited, otherwise it wouldn't 'know' to prompt the user to 'save changes' if comments have been added etc.

Hmm, not sure that is possible.  You could try the Macro recorder and perform your steps manually.  Then, look at the code it generates.  It "may" give you a hint in the right direction.