Hi Jim,
you might use attached DivideCurveLengthEx() method. It should work like the RhinoScript (vb) method and allows to specify an interval.
For the interval you can use a list or two floats or Rhino.Geometry.Interval(t0, t1). Note that the interval is not normalized, as in the RhinoScript (vb) method.
DivideCurveLengthEx.py (1.5 KB)
c.