[Closed] Spline twist/normal

Hey guys!

Back with the splines.
Same situation as before: several hundret splines, which now have a path deformed geometry attached to them.
The problem is that the rotation around the spline axis is rather arbitrary, so I want to set it via script by making the normal of the spline point towards a certain direction.
I could set the rotation value of the path deform modifier, but since I don’t know the original orientation of the path, I don’t know which value I need to set.

Is there a way to get/set the normal of a spline?