I have been using hook_alter to modify forms in a custom PHP module. I started to take the same approach modifying the result page of "node add" form. However this page is not a form so I don't have a form ID to hook on to. Actually it contains a login form, but that does not contain the elements that I am looking for.
Next I cloned the node.tpl.php file called and called it node-my-content-type.tpl.php. If I add "hello world" to this page, the phrase is displayed at the top, so I know it is working.
However, here all my content seems to be flattened to a single string called $content, so manipulating this becomes very difficult.
What approach should I use in this situation?