Something's keeping your Post from posting data. Try posting a simpler form from a new script. Does it var_dump data? If it does, there's something else in the script, with the original form, that's probably causing the problem.
How do you want to do it? Sounds like you have the skill to do it any way you choose to do it. So, just do it. There's no wrong way as long as you have validation.
The short answer is simple copy the page source. Edit to taste. Voila! Instant clone.
The longer answer is learn how to code so you can make those edits. starting with a html tutorial like:
http://www.w3schools.com/html/default.asp
Your "fetch header" is called a Key if I understand you correctly:
http://www.w3schools.com/php/php_ref_array.asp
look for descriptions dealing with Keys..
Your second question will require an if statement:
http://www.w3schools.com/php/php_if_else.asp