This is my source :

<div class='main'><div class='box1'>pippo franco<p>topolino</p></div><div class='box2'>susan elena<p>matteo</div></div>

i'd like to have a regex that can help me to extract from that source only the text between "<div class='box1'>" and the following "</div>", i mean only "pippo franco<p>topolino</p>".

How can i do this with a regex?