I am responsible for distributing a business-sensitive
worksheet and wish to enable the spreadsheet to become
inoperable after a certain date.

A long time ago, I recall that it was possible to install
a "time bomb" in the spreadsheet, that was a macro which
after a certain date deleted lots of pages in the
worksheet and then saved itself onto the existing file
name. That way, after a certain date, anyone trying to
open the file would see the file render itself useless.

I do not know how that can be done in recent versions of
Excel (2000, 2003).

Any suggestions would be much appreciated.