if ($data =~ m/<section1>.*?<parameter>.*?<rstate>(.*?)<\/rstate>/s) {
	print "found first match! '$1'\n";
	#$data=~ s/<section1>.*?<parameter>.*?<rstate>(.*?)<\/rstate>/$newrstate/s;
	$data=~ s/$rstate/$newrstate/s;
}
if ($data =~ m/<section2>.*?<subsection>.*?<parameter>.*?<rstate>(.*?)<\/rstate>/s) {
	print "found second match! '$1'\n";
	$data=~ s/$rstate/$newrstate/s;
}
if ($data =~ m/<section2>.*?<subsection>.*?<subsection>.*?<parameter>.*?<rstate>(.*?)<\/rstate>/s) {
	print "found third match! '$1'\n";
	$data=~ s/$rstate/$newrstate/;
}
	# Print to output file
	print OUT $data;

##</code><code>##

<map>
	<section1>
		<parameter>Some text</parameter>
		<rstate>CHANGE_THIS</rstate>
	</section1>
	<section2>
		<subsection>
			<parameter>dont change this</parameter>
			<rstate>CHANGE_THIS</rstate>
		</subsection>
		<subsection>
			<parameter>dont change this</parameter>
			<rstate>DONT CHANGE THIS</rstate>
		</subsection>		
		<subsection>
			<parameter>dont change this</parameter>
			<rstate>CHANGE_THIS</rstate>
		</subsection>
	</section2>
	<section3>
		<parameter>dont change this</parameter>
		<rstate>DONT CHANGE THIS</rstate>
	</section3>
</map>