Browsing around in the Hammer editor, I found this entity. Tried using it in the same manner as a vgui_screen (which works somewhat okay if you supply a certain file) but nothing happened. Took a look in the code, looks like a file called in the resources folder named "MovieDisplayScreen.res" is required, but it isn't present.

If someone has gotten it working, can you please list out the steps to get it to work? Much appreciated.