I don't know how much liberty you have to change the code, but this modification seems like it would make life a thousand times simpler and is certainly less obfuscated. Instead of "ctitle" you could pass a reference to any structure and it will correctly reference it. It is not quite as strict in parsing the key names but that would be simple to add.

#!/usr/bin/perl

$CONFIGS={};
string_to_struct("CONFIGS-hosting_plans-c-title","ctitle");
print $CONFIGS->{hosting_plans}{c}{title};
exit;

sub string_to_struct {
  my $string = shift;
  my $val    = shift;

  my ($var, $keys)  = split /-/, $string, 2;
 # safety check would normally be here - removed for simplicity

  no strict refs;
  my $ref = $$var;
  use strict refs;

  my $pointer = $ref;

  my @a = split(/-/,$keys);
  foreach ( 0..$#a ){
    $pointer->{$a[$_]} = ($_ == $#a) ? $val : {};
    $pointer = $pointer->{$a[$_]};
  }

  $ref;
}
[download]