>perl -wMstrict -le
"use Data::Dumper;
 ;;
 my %HoH = (
   foo => {
     bar => {
       baz => {
         quux => 42,
         },
       },
     },
   );
 print Dumper \%HoH;
 ;;
 my %my_own_bar = %{ $HoH{foo}{bar} };
 $my_own_bar{baz}{quux} = 'OOPS';
 print Dumper \%my_own_bar;
 print Dumper \%HoH;
"
$VAR1 = {
          'foo' => {
                     'bar' => {
                                'baz' => {
                                           'quux' => 42
                                         }
                              }
                   }
        };

$VAR1 = {
          'baz' => {
                     'quux' => 'OOPS'
                   }
        };

$VAR1 = {
          'foo' => {
                     'bar' => {
                                'baz' => {
                                           'quux' => 'OOPS'
                                         }
                              }
                   }
        };