Two words ... don't bother.

Excel is a sophisticated end-user product but not a secure development tool.
Any protection you can devise can be easily defeated.

--

Vasant


"Don" wrote in message
...
I've installed various programs that allow use for 30 days, then
require registration, or the program won't work. Is there a means to
do this with the Excel sheet that I'm working on? Perhaps a website
where this can be purchased? I hate to be a pain, but when you put a
lot of work into something, you like to have a little control...

Thanx

Don