I just realized I should probably paste the code I had that generated that.I should mention that $d is the path to the dictionary file (with the words to match) and $p is the input pattern (ABBCDE above).

This is pretty ugly

my %charhash;

@letters = split(//,$p);
$string = "";
$invert = "";
$count = 1;
foreach $letter (@letters) {
  if(defined $charhash{$letter}) {
    $string.="(\\$charhash{$letter})";
  } else {
    $charhash{$letter} = $count;
    if($invert) {
      $string .= "([^$invert])";
    } else {
      $string .= "(\\w)";
    }
  }
  $invert .= "\\$count";
  $count++;
}

print "Searching for pattern /^$string\\s/\n";


open DICT, $d;
while(<DICT>) {
        print if /^$string\s/i;
}
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