This example sets the top margin to 72 points (1 inch) for the first section in the active document.
ActiveDocument.Sections(1).PageSetup.TopMargin = 72
This example creates a new custom label and sets several properties, including the top margin, and then it creates a new document using the custom labels.
Set newlbl = Application.MailingLabel. _
CustomLabels.Add(Name:="My Label")
With newlbl
.Height = InchesToPoints(1.25)
.NumberAcross = 2
.NumberDown = 7
.PageSize = wdCustomLabelLetter
.SideMargin = InchesToPoints(0)
.TopMargin = InchesToPoints(1)
.Width = InchesToPoints(4.25)
End With
Application.MailingLabel.CreateNewDocument Name:="My Label"