use strict;
use warnings;

use Data::Dumper;

my $string_containing_needed_matches = 'XXXreYYY' x 3;
my @arr = $string_containing_needed_matches =~ /XXX(re)YYY/g;
print Dumper \@arr;
__END__
$VAR1 = [ 
          're',
          're',
          're'
        ];