Projector Load Window - help!

I’ve got an .exe file and I have a .PDF file that launches off of it when you click a button. The problem is that when the projector file is full screen, the .PDF file loads BEHIND the projector window. Do you know how load files in front of the projector file?

Either that or I need to know how to make the .exe window non-resizable so that the .PDF file is visible behind it.

Thanks!