my %hash = (
    'Version' => ['obVersion', '0x0204'],
    'Stat' => ['obStat', '0x04b4'],
    'Mode' => ['obMode', '0x0020'],
    'Regulation' => ['obRegulation', '0x0014'],
    'Schedule' => ['obScheduler', '0x0001']
);

$hash{'Regulation'} = ['newReg', '0x0015'];
my $p = $hash{'Schedule'};
@$p[0] = 'obUpdater';
$hash{'NewKey'} = ['This', 'Is', 'Four', 'Items'];
delete($hash{'Mode'});

foreach (keys %hash) {
    $p = $hash{$_};
    print "$_ => [" . join(' ', @$p) . "]\n";
}