Excel spreadsheet forwarding

These are always hard questions to answer, because it's not what you want to hear.
The answer is no.
You can protect the spreadsheets with a password that will hide the formulas and not allow any changes to the sheet or parts of the Worbook/sheet.
Look at Tools>Protection. Format the cells you want to allow to change by removing Locked on the Format>Cells Protection tab and then the rest will be locked when protected.

Lotus Notes has a $keepprivate that can be embedded

There are other methods as well:

http://www.westcoast.com/asiapacific/articles/2001_04/reviews/review1.html