expression.RectUnion(Range1, Range2)
expression Required. An expression that returns a Spreadsheet object.
Range1 Required Range.
Range2 Required Range.
Remarks
This method always returns a rectangular range. For example, if you specify A1:A5 and F1:F10, the return value is the rectangular range A1:F10. Also, you cannot use this method to create a range containing noncontiguous areas.