Countries and domestic zones.

Hello.
I use the Zone Rates shipping for International and Domestic shipping.
For International - all OK.(I define countries by ISO_CODE 2).
But for Domestic....
Can I define my Domestic zones by domestic_zone_name or Domestic_zone_code?
Example for file ZONES.php :

// class methods
function quote($method = '') {
global $order, $shipping_weight, $shipping_num_boxes, $total_count;
$dest_country = $order->delivery['country']['iso_code_2'];
$dest_domestic_zone = $order->delivery['domestic_zone']['domestic_zone_code'];
$dest_zone_id;

if($dest_country == "RU") {
   $dest_zone_id = $dest_domestic_zone;
} else {
   $dest_zone_id = $dest_country;
}
  $dest_zone = 0;
  $error = false;

Now it does not work

Thanks

Hi.
May be my question was not correct.
I use Zone Rates module.
How can I use this module for international zones (countries) and domestic zones (states in my country) at the same time?
Best regards...