expression.LeftMargin
expression Required. An expression that returns a PageSetup object.
Remarks
If the MirrorMargins property is set to True, the LeftMargin property controls the setting for inside margins and the RightMargin property controls the setting for outside margins.
Example
This example sets the left margin to 1 inch (72 points) for the second section in the active document.
ActiveDocument.Sections(2).PageSetup.LeftMargin = 72