Move stores to newly created websites

create stores.php

<?php
require_once "app/Mage.php";
Mage::app();

$storeCodes = array('nl', 'dk', 'es', 'fr'); // new websites to be created - also used to get current store IDs
$websiteIds = array(1, 2); // existing websites (default + at)
$rooterCategoryId = 2; // root category for the storeGroup

foreach ($storeCodes as $code) {

    /** @var $website Mage_Core_Model_Website */
    $website = Mage::getModel('core/website');
    $website->setCode("ielm_$code")
        ->setName('iELM ' . $code)
        ->save();
    $websiteIds[] = $website->getId();

    /** @var $storeGroup Mage_Core_Model_Store_Group */
    $storeGroup = Mage::getModel('core/store_group');
    $storeGroup->setWebsiteId($website->getId())
        ->setName("ielm_$code")
        ->setRootCategoryId($rooterCategoryId)
        ->save();

    $const = 'IELM_Common_Helper_Data::STORE_ID_' . strtoupper($code); // constant with the storeID
    /** @var $store Mage_Core_Model_Store */
    $store = Mage::getModel('core/store')->load(constant($const));
    $store->setWebsiteId($website->getId());
    $store->setGroupId($storeGroup->getId());
    $store->save();
}

$productIds= Mage::getResourceModel('catalog/product_collection')->getAllIds();
Mage::getModel('catalog/product_website')->addProducts($websiteIds, $productIds);

echo shell_exec('php shell/indexer.php reindexall');