Its certainly possible to have a UI statically placed relative to the display. The easiest way is to have your worldspace canvas locked to zcore's viewport plane. Its a representation of where the physical display is located in virtual space. The camera frustums pivot on this plane and because of this, any objects locked to it will have the effect of sitting still on the display glass, like a typical UI.
Here's a simple script that should help you get what you're looking for when attached to a world space UI canvas.