Like, you click a button on the website and it contacts your server depending on what the command was set as.
Blockland can give you the html of a website
you can only do things if you look at what the html is
so if a button's action is "post.php" you will have to post to that website using TCP objects and send the appropriate information
I don't think you can do anything about what the website runs to generate what is sent, but I do know that you can read what is sent