If you are talking about Fredo6's Bezier Spline it is a very complex plugin and can do many things. You may want to look at the tutorials for it. You can certainly add as many control points as you want. Even a simple double click on the orange line will add another point. http://sketchucation.com/forums/viewtopic.php?p=100509#p100509

@massimo said: Well if the objects are quite simple as you show you can try this one. thank you very much for quick reply this plugin is what im looking for this solve scenario 2