PolyTools provides some utilities to make changes to polylines like: 

• Convert a 2D polyline to a lightweight polyline and vice versa.
• Convert a 2D polyline to a 3D polyline.
• Convert a 3D polyline to a 2D polyline.
• Change the initial point of a closed 2D polyline.
• Change the initial point of a closed 3D polyline.
• Break lines and 2D polylines to its intersections.
• Export lines, 2D and 3D polylines vertices to an Excel file. 

Please go to www.oldbridgesoft.com/polytools.html for more information.