Hi,
if you want a software solution for business purposes you should be using Mach4. It ability to be customized far far exceeds Mach3.
Having said that I'm not aware that Mach , 3 or 4, has that kind of password protection.
The solution I'm thinking that may be applicable to you is to use Mach4 to write another screen, but with only those components you want your customer
to access but have another fullblown screen that share the same .ini file.
I noticed in another of your posts that you asked the nature of Mach3, Visual C++. I don't think you will ever get the source. In any event the source code had
become very unwieldy and that was the reason that Mach4 was written.
Craig