Returns or sets the distance from the top of the page to the header, in points. Read/write Double.
Margins are set or returned in points. Use the InchesToPoints method or the CentimetersToPoints method to convert measurements from inches or centimeters.
This example sets the header margin of Sheet1 to 0.5 inch.
Worksheets("Sheet1").PageSetup.HeaderMargin = _
Application.InchesToPoints(0.5)