Tube or Curve that has 2 points of contact (2 anchor points) for 2 different parent objects

When I create a curve or a tube that ie. connects a backpack and a gas mask on a figure. I can set the parent point to only one end mask or backpack If I move mask(head) it will move along with it, I would like to have an option to keep the other end anchored to the other object as well. So the curve would stretch (interpolate) between them.