Go to the VBE

From the Tools menu protect the project with a password and save.

The next time the workbook is opened it will require a password to view
the code.

But remember a serious "hacker" can get in...

How can a "serious hacker" get the data? I mean, just playing a little
bit with an hex editor or what?

Yes - easy to find the method with a little googling


I used to program in Visual Basic years ago, and I remember that there
were something called OCX controlls(compiled code), wich can be embebed
into any MS office application. Are them still there in VB net?


In VB or VB.net you could wrap your code into a dll and use that from within
Excel. That would be much more secure than VBA.

Tim