From what you are describing, you shouldn’t be using the pin feature at all. Instead, move the lightbox to where you want it before you show it. In the attached example I’ve added a Move action to the OnShow event of the lightbox panel. The formulas in the Move action moves the panel to the center of the window on x, and to Window.scrollY + 100 on y. There is a button part way down on the page that will show the panel using the lightbox option.
The beauty of putting the positioning in the OnShow event is that anything can show that panel and it will just appear where you need it.
Hope this helps!
ScrollableLightBoxExample1.rp (60.9 KB)