"Pdek" wrote...
What's the difference between Excel 1997 and Excel 2002 (in brief).
Is there a way to save a 2002 version file so it won't open in 1997 version
program?
....

Excel 97 can open workbooks created by newer versions. You could use macros
to check Excel version and close the workbook under Excel 97, but users can
disable macros.

Always best to design and implement for the *OLDEST* version of software in
use, meaning you should have developed using Excel 97. If your workbook
works in Excel 97, it's a near certainty it'll work in newer versions.

As for large numbers, always design for boundary conditions. Even if most of
your fields only need to show 5 or fewer digits, if some need 8 or 9, then
your column widths need to accommodate 9.

As for selecting protected cells, do you mean you have worksheets that look
like forms/dialogs, and selecting protected cells destroys the illusion?
Again, you could use macros, specifically SheetSelectionChange, to return to
the first unprotected cell if the user selects a protected cell.