In MEP2016 Plus/Premium, select the object that will be the overlay, right-click, select "Attach to picture position in video..." A screen will appear with instructions. Read them carefully. Also, if you don't know how to do keyframing, this is the moment to learn all about it. See the manual.
For more information, in F1 manual, Search, lookup "Position" and on the list will be "Attach to picture pos...."
Since you are new to MEP, you should also review my tutorial on Getting started in the Tutorials tab of this forum. It applies to 2016 as well as 2015 and earlier versions.