If you have an overset story myStory, then this:
add an anchored frame at the end of the story.
you can move() the parent (character) of the anchored object.
I wasn't clear enough. I have an existing textFrame or graphicLine that is not anchored and I would like to anchor it to text that is overset. The reason is because I need to set the geometricBounds, so I was thinking I could set it and then anchor it, but I don't see any way except for app.cut().
Ah, I see now Harbs did give a solution. First anchor it to the begining of the story and then move it to the overset insertionPoint. Perfect!
You can create it inline in a dummy story which isn't overset and then use move()