#!/usr/bin/perl -w
use strict;

my $text ="some text START text I don't want START only text I want END";

my $wanted  = ($text =~ /.*START (.*) END$/)[0];
my $wanted2 = ($text =~ /.*(START .* END)$/)[0];

print "wanted=\"$wanted\"\n";
print "wanted2=\"$wanted2\"\n";
__END__
prints:
wanted="only text I want"
wanted2="START only text I want END"

##</code><code>##

my ($x,$y) = ($text =~ /.*(START (.*) END)$/)[0,1];
print "x=$x y=$y\n";
#prints: x=START only text I want END y=only text I want