Hi Diane,

As Jim says an ActiveX dll or Com dll is very hard to crack but if the
intention is to create an xls there will be nothing to stop the user from
copying and saving the xls. However if major functionality is controlled
from the dll, eg no formulas in the xls and calc's done in the dll, then
this would indeed be a good way to protect your intellectual property.

You'd also need to devise a means of unique registration tied into the
user's system, otherwise nothing to stop the dll being passed on freely.

Altogether quite a learning curve and you'd need to acquire VB6, eg MS
Visual Studio 6 from eBay. You might want to weigh all this against the
potential loss with your VBA & xls protected to the maximum. Although for
most reading these ng's that protection is effectively nothing perhaps a
fair proportion of those willing to pay in principle would not attempt to
cheat you.

Regards,
Peter T


"Diane" wrote in message
...
compile a COM object ... is there somewhere i can find instructions of how
to
do this?

"Jim Thomlinson" wrote:

Was the advice to create an addin or a COM addin. A regular addin has
little
more security than a regular spreadsheet... COM addins are pre-compiled
and
much more difficult (darn near impossible) to crack...
--
HTH...

Jim Thomlinson


"Diane" wrote:

I would like to make one of my spreadsheets available to be purchased,
but do
not want others to save it & give it away.

I got some good advice to create an add-in for this spreadsheet to
lock it
down a bit, but am not exactly sure how to do it. I followed the msdn
instructions of how to save a file as an add in, but am unsure how to
have it
open a spreadsheet without allowing it to be changes/saved and without
having
the spreadsheet be accessible.

Any help would be greatly appreciated.

Regards,
Diane