Not possible. To answer why that's impossible, imagine:
- I include an iframe to some very important business (let's suppose for a moment this business does not have frame-busting code)
- When the user reaches my page, it begins manually controlling the cursor's position to highlight the "Delete Account" button, and simulates a click.
- User's account is deleted on a completely different site, through none of their input.
It might help us to know if there's some specific reason you'd like to do this - possibly the solution is not what you think it is. For instance, if you are trying to make an FPS using WebGL, I seem to remember Chrome including some function to allow for mouse control inside of a window (possibly taking a browser confirmation dialog)