Heres something I cannot do, is it even posible

I have 2 curves (light yellow) that I want to connect with a 3rd curve (light pink) that I have drawn - I snap the end points no problem but is there a way to contunue the curves shape so that the 3 curves looks totaly smooth.

Like maybe some kind of snap guide that is projected from the end points on the (light yellow) curve?

I suppose this is just like blending the shapes together, but I want to do it manualy with very curvy curves, not simple curves.

Cheers!