Adobe After Effects is frequently used to do more advanced chroma key virtual sets composites because of it's toolset is broader than an editors for keying and layering. I'm going to walk you through the steps of making a basic set using Studio 159, a news room from virtualsetworks.
To start, create a project at the resolution you will be working at, in our case we will be doing HD1080. Import the footage of your talent on greenscreen and some footage to display out the main window and something for the screen on the desk. Next we need to import the virtual set.