Auto Form Fill on separate site

I have no idea what programming language can be used to do this... I need to have a form automatically filled on another website I do not own. I own the website where someone can fill in a form. I want that information to automatically be sent to me via email (which i can do) and I want the information to post to the form on the other website. The problem is I cannot put any code in the other website. I have no idea if this is even possible. Tony