Hi Will

If the user can see the formulas then the user can see the value of the
parameters, wherever they come from, by highlighting the relevant part
of the formula in the formula bar and pressing F9.

To prevent that you need to hide the formulas and protect the
worksheet:
Format / Cells / Protection / Hidden
Tools / Protection / Protect Sheet (with a password)

If the user is to be allowed to change some cells then they first need
to be unlocked on Format / Cells / Protection before the sheet is
protected.

If you had a worksheet containing the values of the variables you don't
want the user to see (which could be the result of simple linking
formulas) you could then hide that worksheet from the user.
Format / Sheet / Hide
and protect the workbook structure
Tools / Protection / Protect Workbook (with a password)

The formulas in the user-visible worksheet would reference the copies
of the variables in the hidden sheet (I would name the cells concerned
for clarity in the formulas).

You can break the link before sending the workbook out and the values
in the hidden sheet will be preserved.

Hope this helps


Bill Manville
MVP - Microsoft Excel, Oxford, England
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