Adding a video within a rendered animation

I’m making an animated short for a crowdfunder project and I need to make a scene where I have a character sat at a desk in a room with the wall behind the character as a video that is playing as if there is a projector, projecting the video directly on to the wall.

How could I do this? I’ve tried searching but don’t really know what terms to use. All I need is a nudge in the right direction. Please help

Forgot to mention that the camera will be panning in so almost needs to be something like a video texture if that makes sense

You know… you could try compositing the projected video in post production and since the camera will be moving you might have to track the wall or the screen on which it is being projected, so that the video sticks to the wall.

I hope this helps you somewhat.
All the best.