expression.SplitVertical
expression Required. An expression that returns a Window object.
Remarks
To remove the split, set this property to zero (0) or set the Split property to False.
Example
This example splits the active window so that the top pane occupies 70 percent of the window.
ActiveDocument.ActiveWindow.SplitVertical = 70
This example splits the window for Document1 in half vertically.
Windows("Document1").SplitVertical = 50