Joannesalfa, not annoyed just busy. If you can't figure things out maybe someone else can help while I'm gone?
Quick answer for now... make an input in c2, set id my_c2input, and give on click event with event sheet
example on clicked call my_callback_function
Then with your other input (the one not inside c2) have it click my_c2input by giving it an onclick="my_c2input.onclick();" either inline or with javascript.
and about the callFunc code just open browser console and test a bit or ignore it for now. Sorry can't help more right now.