An integer specifying the position of the row in the worksheet.
Each worksheet contains 1,048,576 rows stored in the collection returned by the Worksheet.Rows property (the RowCollection object). You can access an individual row by its zero-based index or heading (see the How to: Access a Row or Column example).
The Index property returns the row index. To obtain the row heading displayed at the left of a worksheet, use the Row.Heading property.
To obtain the index of the row that contains the specified cell, use the Cell.RowIndex property. To get indexes of rows that border the cell range, use the CellRange.TopRowIndex and CellRange.BottomRowIndex properties.