# assuming
our %dictionary = read_dictionary_file_to_hash($dict_file);
our %tiles = read_tile_file_to_hash($tile_file);

# here we go
our $tile_regex = convert_tilehash_to_regex(\%tiles);
our %filtered_dictionary;

for my $word (keys %dictionary)
{
    my $sorted_word = join('', sort split '', $word);
    $filtered_dictionary{$word} = 1 if $sorted_word =~ $tile_regex;
}

sub convert_tilehash_to_regex
{
    my $tile_hashref = shift;
    my $tile_regex_string = '';
    for my $tile ( sort keys %{$tile_hashref} )
    {
        $tile_regex_string .= "$tile{0,$tile_hashref->{$tile}}";
    }
    return qr/^$tile_regex_string$/i;
}

##</code><code>##

# in init section
our $BLANK_TILE = '#';

# in convert_tilehash_to_regex
        $tile_regex_string 
          .= "$tile{0," 
            . $tile_hashref->{$tile}+$tile_hashref{$BLANK_TILE}
            . "}";