>Is there a corresponding VFP command or commands for the Save As Class dialog
>of the Modify Form?

Sort of.

MODIFY FORM fred NOWAIT
ASELOBJ(laForm, 1) && Get object reference to the form in the designer
loForm = laForm(1)
loForm.AddObject("Text1", "Textbox")
loForm.SaveAsClass("MyVcx.vcx", "MyForm", "My saved form")
MODIFY CLASS myform OF myvcx.vcx