How to add a fixed position box displaying lat long of an object over time


I am trying to add a box to the viewer that displays the lat/long of objects pulled from czml. I see how I can add a billboard to an object and display information but I don’t see how I can add a box that is fixed on the viewer that can have the the lat/long of multiple objects. I can overlay a box on the viewer with html but I need it to be displaying the current lat/long based off of the viewer’s clock.