OutlineLevel Property [Excel 2003 VBA Language Reference]
Returns or sets the current outline level of the specified row or column. Read/write Variant.
Remarks
Level one is the outermost summary level.
Example
This example sets the outline level for row two on Sheet1.
Worksheets("Sheet1").Rows(2).OutlineLevel = 1
Applies to | Range Collection
See Also | ApplyOutlineStyles Method | AutoOutline Method | ClearOutline Method | DisplayOutline Property | EntireColumn Property | EntireRow Property | Group Method | Outline Object | ShowDetail Property