Ignore Excel Version on ActiveWindow.Close

Hi,
I'm cycling through approx 500 old excel files (various versions) and extracting (by select, copy, paste) certain ranges from each.
All the files have the same name and I'm opening, extracting and closing each one in order.
This is all via a Macro.

As some of the files were created in older versions of Excel I'm prompted each time to choose to recalculate the workbook at CLOSE.

My request is for any help in having Excel ignore the recalculate at close so I can kick off the macro and not have to manually intervene.

I'm guessing the solution is in 'BeforeClose' event handling but don't know how to use this..

Any and all suggestions welcome