Below is a sample code that shows how it can be done. You, obviously, will use your framework classes.

oForm = CREATEOBJECT("Form")
oForm.AddObject("pgfNew", "PageFrame")
oForm.pgfNew.PageCount = 3
oForm.Visible = .T.
oForm.pgfNew.Visible = .T.

>How can I create a Pageframe on a Form