sub my_sort_index {
    my ($c, $d) = @_;
    # We want any item starting with "index." to sort to the top of
    # the list.  The rest of the ordering is handled by the caller.
    # So there are four cases we must handle:
    #
    #   Matches?
    #   $c    $d   return
    #   No    No     0 
    #   Yes   No    -1
    #   No    Yes   +1
    #   Yes   Yes    0     (-1 + +1 == 0)
    #
    # In the fourth case, when both strings have the "index." prefix,
    # we want them to sort via the normal method so that "index.1" will
    # always sort before "index.2".

    my $return_value = 0;
    --$return_value  if $c =~ /^index\./;
    ++$return_value  if $d =~ /^index\./;
    return $return_value;
}

##</code><code>##

my @sorted = sort { my_index_sort($a,$b) || $b cmp $a } @list;

##</code><code>##

sub convert_name_to_L_F_M_Extras {
    # Lots of ugly code to split the name into bits, determine which bit goes where, and
    # return an array of [ LastName, FirstName, MiddleName, Extras ], like so:
    # "Dr. John Smith" => [ Smith, John, undef, Dr. ]
    # "Eucalyptus A. Tree, Esquire" => [ Tree, Eucalyptus, A., Esquire ]
    return [ $last, $first, $middle, $rest ];
}
my @list = ( "Dr. John Smith", "Eucalyptus A. Tree, Esquire", "Roboticus", "Lady Aleena, Baker of cookies" );

my @transformed_list = map { [ convert_name_to_L_F_M_Extras($_), $_ ], } @list;
# Now looks like:
# @transformed_list = (
#    [  [ "Smith", "John",       undef, "Dr"      ], "Dr. John Smith" ],
#    [  [ "Tree",  "Eucalyptus", "A.",  "Esquire" ], "Eucalyptus A. Tree, Esquire" ],
#    ...
# );

sub sort_by_name {
    # $a and $b contain an arrayref, the first entry has an arrayref with last, first, etc.

    # Sort by last name:
    $a->[0][0] cmp $b->[0][0]

    # If they have the same last name, sort by first name:
    || $a->[0][1] cmp $b->[0][1]

    ... etc ...
}

my @sorted = sort {sort_by_name($a,$b)} @transformed_list;

# Now throw away the transformed names and keep only the list of sorted names.
@sorted = map { $_->[1] } @sorted;