Document.TopMargin Property (Visio)
Specifies the top margin when printing a document. Read/write.
If UnitsNameOrCode is not provided, the TopMargin property will default to internal drawing units (inches).
The TopMargin property corresponds to the Top setting in the Print Setup dialog box (on the Design tab, click the Page Setup arrow, and then click Setup on the Print Setup tab).
Units can be an integer or string value such as "inches", "inch", "in.", or "i". Strings may be used for all supported Microsoft Visio units such as centimeters, meters, miles, and so on. You can also use any of the units constants declared by the Visio type library in VisUnitCodes.
For a list of valid integer and string values, see About Units of Measure.