In my special case I don't want to let the moving entity leave the path. It should always remain onto the line between the nodes, but my problem is as follows:

When clicking left mouse button I scan from the mouse position for the nearest path in range. This is set as destination. That works fine so far.

But I have to set a lot of path nodes in WED so that the distance between the point I really clicked at and the chosen path I set as destination is not so big.
I'd like to get rid of setting such a lot of nodes and just break down also that world points into one dimension so that the point I clicked at lies onto the line between the two nodes.