[Houdini]Creating a parameter out of spline Chop in Houdini

Hey Guys,
I have created an L-system tree tool and now I am creating a user interface for it. So I have a spline chop controlling the no of generations in each point of the tree. I want to create a parameter for the spline chop. I was thinking of using a float ramp to refer to the spline CHOP but I cannot find a way to control the spline CHOP outside the motion view window. Does anyone know a way to do that?
Any or all suggestions will be much appreciated.
Thanks,
Regards,
Soumitra