my $arr = [[qw/name pos loc age/],
	   [qw/ike boss 12 44/],
	   [qw/mat slave 22 21/],
	   [qw/jill sec 15 32/],];

my $add = [[qw/car dog age/],
	   [qw/a1 grr 3/],
	   [qw/s2 miew 7/],];

my ($arrfld,$addfld);
for ($i=0;$i<@{$arr->[0]};$i++){ $arrfld->{ $arr->[0]->[$i] } = $i }
for ($i=0;$i<@{$add->[0]};$i++){
  unless ( $arrfld->{ $add->[0]->[$i] } ){ 
    $arrfld->{ $add->[0]->[$i] } = scalar(keys %$arrfld);
  }
  $addfld->{ $arrfld->{ $add->[0]->[$i] } } = $i;
}
foreach my $row (@$arr){
  for($x=scalar(@$row);$x<scalar(keys %$arrfld);$x++){push @$row,""}
}
shift @$add;
foreach my $row (@$add){
  my $nr;
  for ($x=0;$x<scalar(keys %$arrfld);$x++){
    $nr->[$x] = defined($addfld->{$x})?$row->[$addfld->{$x}]:""; 
  }
  push @$arr,$nr;
}