Automatic form filling task

Today when I reached tcc, Sir gave us task for automatic form filling on a website from a datasheet. Everyone was working on this. I too was trying to find out the ways and wanted to make a script in C++ for this task, as the only language I know. I found a way to attach an XML file so as to read the data directly from it and upload to some other but had no idea what to do next. Some other made a script in php, but no one succeeded to make a program that can fulfill the requirement of Sir. Then Sir gave us task to manually enter data into a form online, and really it was like punishment :(. I will definitely work to find its solution, as entering such type of data is so boring and totally wastage of time.