Replacing a window is a very common type of set extensions. It allows you to convert your budget hotel room into that New York City apartment. All you need is a photograph of a few skyscrapers to composite into the scene.
Tracking and masking are the two challenges on this task. This tutorial example has a moving and rotating camera. Even so, a simple point tracker in Fusion can get a convincing match moving result. Then you can scale the picture to fake some parallax movement between foreground and background.