here is quick step by step:
– create your path in Illustrator
– drag the Ruler Origin to the center of your paths (doing this makes your spline come in centered in C4D)
– save your file (or a copy) in Illustrator 8 format
– Open or Merge this .ai file in C4D
– if you get multiple splines C4D choose Objects > Connect from the Objects Manager menu. this creates a single new spline
– make this spline a child object to an Extrude Nurbs
– adjust the Z Movement of the Extrude Nurbs
there may be some gotchas, but this is basicly it.
sascha