Gitano said:
Is there any way to protect some worksheets with a pasword that can not be
breaked?
No. Internal passwords are easily broken.
You could make things annoying for users who unlock worksheet by using
udfs which check whether specific worksheets are protected or not and
return error values if they're not protected or Empty (effectively the
same value as blank cells) otherwise, then call such udfs from every
formula so that all formulas return errors when any worksheets that
should be protected aren't. However, there's no way to stop users from
replacing your password with one of their own.
