A hash of hashes should do the trick 
use Data::Dumper;

my %hash = (
  ABC => 'foo',
  DEF => 'bar',
  XXX => 'baz',
  YYY => 'quux',
);
my %casehash;

for(keys %hash) {
  $casehash{CaseA}->{$_} = $hash{$_}
    if /^[A-F]+\z/;
  $casehash{CaseZ}->{$_} = $hash{$_}
    if /^[W-Z]+\z/;
}

print Dumper(\%casehash);

__output__

$VAR1 = {
          'CaseA' => {
                       'ABC' => 'foo',
                       'DEF' => 'bar'
                     },
          'CaseZ' => {
                       'XXX' => 'baz',
                       'YYY' => 'quux'
                     }
        };

[download]
You might want to setup another hash to map your ids to their appropriate case groups. See. perldsc for more info on data structures in perl.
HTH

_________
broquaint

In reply to Re: How to group keys by hash value by broquaint
in thread How to group keys by hash value by Anonymous Monk

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