my %hash = (
            '.111' => 'Aaaa',
            '.222' => 'Bbbb',
            '.333' => 'Cccc'
           );

$hash{$_} = substr $hash{$_}, 2 for keys %hash;

##</code><code>##

print Dumper \%hash;
-- -- -- -- -- -- -- --
$VAR1 = {
          '33' => 'Cccc',
          '22' => 'Bbbb',
          '11' => 'Aaaa'
        };