Desktoping

Hello, my name is Jose and i am from Portugal. My need is to change simultaneously the images of all desktops of monitors in the universities. I am creating the front office of the website but I need the engineering that makes the process of automatic exchange of images on the computers desktops. So I need an API, which in the future will be integrated into the website that do the following: - Replace all monitors desktop to the same image; - Get display a second image different for a second login the same person; - Get set a homepage for all computers in the university; - Set an image to all computers when the computer is in sleep mode. This API must be installed on the central computer at college. It will also be installed in several different university, then it must allow choose a different image for all computers in college. Summary: I want to put a digital flyer on computers college X, Y, Z. O the website, i choose computers of college X, Y, Z. I upload the flyers and define the link I want to homepage. All this done through a website. The API, automatically exchange data in all these colleges X, Y, Z, after being installed this API in the central computer college.