#! perl -lsw
use strict;

my @reps = map{ sprintf '%05d', $_ } 0 .. 20;
while(<DATA>) {
	my $n=0;
       # redundant /e option  removed 
       # per [Abigail-II]'s comment below.
	s/\d{5}/$reps[$n++]/g;   
	print;
}
__DATA__
00000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00000xxxx00000xxxxx00000xxxx00000xxxxx00000xxx00000xxx00000xx00000xxx00000x00000x00000