I'm very new to VBA... please really explain your answer to me.

I would like to write some code that recognizes when a user is attempting to
close a particular spreadsheet. (This spreadsheet is updated from ACCESS and
can not have any formulas added to it for ACCESS to feed it correctly.) So I
would like any formulas removed even if the user saved them when the
spreadsheet was open, and then complete the close process.

How do I get VBA to recognize that the user is attempting to close the
spreadsheet?
How do I get it to complete the Sellect All & Clear operations before it
closes?
Then I'm sure I'll have to tell it to save and close...

Any help you can provide would be appreciated!