Self automation for free web hosts is asking for a disaster. You'll get spammers, porn peddlers, and a lot worse. Try posting your questions on www.freewebhostingtalk.com, a sister message board to this site, where people experienced in running free hosts might help you
To answer your question you'd have to use PHP as it's a scripting language, whereas HTML is just used to display webpages.
Its not a company really its just something I do on the side and I am very knowledgeable about web hosting its just that before nothing was automated and because of that it requires alot of work from me to take care of user stuff because I have so many people wanting to use my service