Spline with trough points, even in editing, maybe with Bias handles?

 From:  Heiner (BILDERMENSCH)
6796.1 
Hi there,
I am having every once in a while problems when creating a spline with trough point.
Usualy I am roughing out my shapes and then modify the controll points into my desired
shape.
The problem is that while editing the controll points are not on the spline anymore, but outside
which makes it tough to get the desired shape especialy if you are working with a network of
splines.
The thing i am dreaming of would be splines which keep the controll points on the spline and
super exiting would be to have bias handles for each CP.
Is there any plans to implement such a kind of spline?

Best regards
Heiner