Select the PageNumber object and then apply formatting to it as you would any other selection : Document Header Footer « Word « VBA / Excel / Access / Word
Select the PageNumber object and then apply formatting to it as you would any other selection
Sub pageNumber()
ActiveDocument.Sections(4).Headers(wdHeaderFooterPrimary) _
.PageNumbers(1).Select
With Selection.Font
.Name = "Impact"
.Size = 20
.Bold = True
End With
End Sub