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

my @data = [
   '17-02-2005','18-02-2005','19-02-2005',
   '20-02-2005','21-02-2005','22-02-2005',
   '23-02-2005','24-02-2005'
];

my %labels = (
   'C' => [0,0,0,0,7,0,0,2],
   'A' => [0,0,0,0,0,0,5,4],
   'B' => [0,0,0,0,0,0,0,0]
);

foreach my $item (sort {$a cmp $b} keys %labels) {
   push @{$data[$item]}, $labels{$item};
}

use Data::Dumper;
print Dumper @data;

__OUTPUT__
$VAR1 = [
          '17-02-2005',
          '18-02-2005',
          '19-02-2005',
          '20-02-2005',
          '21-02-2005',
          '22-02-2005',
          '23-02-2005',
          '24-02-2005',
          [0,0,0,0,0,0,5,4],
          [0,0,0,0,0,0,0,0],
          [0,0,0,0,7,0,0,2]
        ];