Here is what I found:
1. this forum article itself in the forum
2. A wiki titled "Handle multiple WinForm forms in Visual COBOL"
3. A forum article "using 'Call' in Method
4. A wiki article "Visual COBOL for Visual Studio Getting Started with Solutions, Projects and the COBOL CALL Statement - Managed" that included a "2433_Visual COBOL Call Managed Tutorial.zip" and some related wiki articles covering other types of mixed calls, etc.
From these, I gleaned what I needed to know. Sometimes it isn't very easy to find what you are looking for in the "official" Doc.
Thanks