Hi Mark,
Thank you for your fast answer. From my poor understanding on cubic spline (I'm not that good in math), a cubic spline will take a set of points and a speed and calculate the correct curve according to that data. CubicSpline seem to draw the curve I need, but I still need to make the correct calculation to determine the curve to draw.
If cubic spline is not available in Esri, than CubicBezier is a good work around for my case.
Regards,
David