Rich,
The trick here is to activate page 3 of the pageframe and then setfocus to the textbox. Put this in the click event of the cmddegridadd button and try it.
IF NOT DODEFAULT()
RETURN .F.
ENDIF
With This.Parent.Parent
.ActivePage = 3
.Page3.txtThing.SetFocus()
EndWith
Kendall Webb
Senior Software Engineer
MCAD.Net/MCSD.Net