script to change normal direction???

it seems there are scripts for pretty much everything. and i can't imagine how people could not need a script for this - I need to take splines i have from scenarios where I have open edges from meshes and I extract them, and change their normals - so that the bounding box will be oriented to this geometry. Often times these are planar but the bounding box does not respect the geometry's orientation. The advice I have gotten is that i need to redraw the geometry but that seems like alot of work. Anyone seen anything that will do this?