expression.SetAsTemplateDefault
expression Required. An expression that returns a Font or PageSetup object.
Example
This example sets the character formatting in the selection as the default.
Selection.Font.SetAsTemplateDefault
This example changes the left and right margin settings for the active document and then sets the page setup formatting as the default.
With ActiveDocument.PageSetup
.LeftMargin = InchesToPoints(1)
.RightMargin = InchesToPoints(1)
.SetAsTemplateDefault
End With