Daniel CHEN wrote:
I have spreadsheet application and want to protect the VBA code. I know how
to use password to protect it, but the password is pretty easy to be cracked
(use commerical software).

It there another way to protect the code and make it difficult to crack?

i don't know it, either.
the protection of vba-project doesn't encrypt source code.
(excel's file protection doesn't encrypt it, too)
the flag of protection is only hoisted.
it is easily removed by something like one line of perl
without any analysis.

how about making DLLs for the main part of the application
from other tools which produce machine code (c++, vb, etc),
and vba procedures for calling DLLs?
however, still it is possible to crack. we shouldn't put
secret things in a software which will be distributed.

--
HTH

okaizawa