Run it as a CGI-script via a simple http call, AJAX, whatever - with the coordinates you want to move the mouse to, eg:
http://localhost:9876/cgi/mousemover?x=200&y=450
PS: For any problem, there are hundreds of excuses as to why, and how - it can't, and shouldn't - be done.. But in this infinite universe, it's really just a matter of determination - as to whether YOU will make it happen.