Does anyone know how to create a helix that is curved?  I need to make a helix to be used as a extrusion/weldment path that starts out straight, goes through a curve and then ends up straight again.  An added complication is that the curve is not an arc but a clothoid spiral so I cannot make a straight one and then flex it.

I’ve included screen shot of an approximation done in (yes I’m going to say it) AutoCAD…