Use the System Exec vi, (in the communications palette) with a command line of c:\winnt\system32\notepad.exe, for example (actual mileage and paths may vary). There may be other tags you can put in the command line to have notepad open an existing file if you need to. I think this vi exists in 6, I am using 7.1, all else fails use Help to search for it.

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

can you embed notepad (win32 app) into a VI GUI?

At first I was going to suggest Notepad embedded via an ActiveX container, but I saw no Notepad feature to insert.
Maybe if you created an Active X wrapper in VB for Notepad then call it via the container it may work, not sure.

Alternatively, you could also use a large string or text control to display and edit text then save it's contents to a file if needed.

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

In lieu of Notepad, you can embed an MS Word document in the GUI with an ActiveX container (If you have MS word).

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

Notpad is only an example in my case.  
Specifically I'm thinking of putting a Graphical Perl App that I have compiled into an exe.  

Any pointers (rtfm) for constructing activeX containers?