path curve for IK chain

nyashmash91

Hello everyone. There is a "snake" object (or a "rope") consisting of consecutive bones. I want to make a control element (torus) through which this snake should move. There is an IK chain in the head of the snake. I need to move the torus and the snake to crawl into it and through it.

If I bind the IK chain node to the torus, then everything goes well until I start to bring the torus closer to the snake's head (the distance between the IK chain node and the torus is fixed and everything breaks). That is, I need the IK chain node to move along a curve passing through the hole in the torus. Is there any functionality in DazStudio that allows you to move a node along a given curve (a curve between several control points) in the editor?