"Monsters" travelling along a path?

How would I make sprites travel along a certain path? I am trying to make a few sprites travel along a line, just can't figure out how to do it.

There are many ways, a quick fix would be to give your monster sprite bullet behaviour and set up an event that would redirect the sprite upon contact with an invisible "waypoint" sprite.

there is some plugin with this function :

(from Pode)

http://www.scirra.com/forum/behavior-splinepath_topic49867_post313984.html

Which tool is being used here in the plugin..?? If this function works then it will be easy for the monsters to travel along the path.