SplitColumn Property
From Microsoft Excel Visual Basic
Returns or sets the column number where the window is split into panes (the number of columns to the left of the split line). Read/write Long.
Example
This example splits the window and leaves 1.5 columns to the left of the split line.
Workbooks("BOOK1.XLS").Worksheets("Sheet1").Activate
ActiveWindow.SplitColumn = 1.5