This discussion on the WebmasterWorld forum is in keeping with what
I'm aware of, and suggests that "the simple answer is no", and that
you'd be better off having recipients sign a "draconian" non-disclosure
agreement, and be prepared to sue them if they violate it:
The only program I ran across which sounded even moderately effective
was FileConfidante! by Kilowatt Software L.L.C., but it's not clear,
to me, from the page, whether it would work with your scenario, given
the implication that you want your users to be able to input data:
"Secured files are encrypted on your system.
An internet-based pre-installation process prepares a secure key for
the target system 1.
Secured files are decrypted on the target system,
by a supervising program that verifies the target system's key.
After the key is verified, the supervising program starts a viewer
for decrypted files [Other applications can process decrypted files,
not just viewers].
Decrypted files are automatically removed, after viewing."
You might try contacting them to see if the use of their
software will allow you any protection under the parameters
of your specific situation, but if the result data itself is
what you're trying to protect, after they've entered their
personal data to arrive at those results, it doesn't seem
likely that this program will provide you any real protection.
If I'm way off base in understanding your question, or if
you have any questions about my response, please post a
Request for Clarification.
Additional information may be found from an exploration of
the links resulting from the Google searches outlined below.
Searches done, via Google:
excel "copy protection"
Clarification of Answer by
10 May 2006 21:26 PDT
I thought that implication was clear from my responses, but I was
able to locate yet another post on an MS Support Newsgroup, that
is quite specific to your question, addressing the issue of not
allowing an Excel file to be copied from a network location. Once
again, the answer is no, unless you literally deny those who access
the file permission to write to any part of their systems:
Naturally, if they're able to write data to the file in order to
chart results, then they have write access.
Also discussed is hiding the Excel file but making the data
available in another form. Obviously this would prohibit the
user from utilizing the spreadsheet by entering data and getting
a scenario back.
Unless I'm being truly obtuse here, there is simply no way to
prevent an accessible Excel file from being copied and still
be used in the way I'm understanding your intentions to be.