#!/usr/bin/perl
use strict;
use File::Find;
use warnings;
my @file=("hh","yy","zz","aa","bb","hh","yy","zz","aa","bb","hh","yy","zz","aa","bb");
my $i=0;
$string="
hi hello @begintobe 
replace @end asas x x x x x zxzxax
hi hello hi hellooo
@beginthis has tobe 
replaced @end";
my $x=$file[$i];
		while ($string =~ s/\@begin([\w\W]*?)\@end/$x/ge) {
        $i++;
		$x=$file[$i];
		 print $i."\n";
        }
print $string;

##</code><code>##

##output
hi hello hh asas x x x x x zxzxax
hi hello hi hellooo
hh