Does exist a trick for change the curve A in the curve B except redraw all?

The two curves have same points of references (and it's not corner points)
Seems points can't be jointed to a curve :(

As soon as moving controls points of curve's A, curve goes away of the landmark Points :(

I know that is more Bezier curves' system but is there a trick to mimic it?

Or I miss something :)