Paul,

what you want cannot be done, because the macro warning should protect
against virusses. If it was possible, they would be the first to use
this feature;)

What *is* possible is the following setup:

Have 1 sheet visible containing the text " Enable Macro's". All other
sheets should be set to "very Hidden"

On opening the spreadsseet your open macro should hide the visible
sheet and show the hidden sheet(s). Users can still open your file, but
it is of little use to them unless macro's are enabled.

Another option is to sign your VBA project digitally, this will allow
execution of the VBA code regardless of security settings.

DM Unseen