RE: Winforms: calling 2nd form

The call statement is used to execute COBOL procedural programs as subprograms.

When you want to call a method in a COBOL class such as a Windows Forms class you need to instantiate the class as an object and then invoke its methods using the COBOL invoke statement.

You might want to take a look at the managed COBOL Concepts section of the docs here:

Example:

       method-id button1_Click final private.
       01 myform  type testform2.Form2.
       procedure division using by value sender as object e as type System.EventArgs.
           
           set myform to new testform2.Form2
           invoke myform::ShowDialog