Magento: Redirect to product in specific language

# create a new file ./getProductEn.php
<?php
require '../../app/Mage.php';
 
try {
    $app = Mage::app('gb');
 
    // check sku
    $sku = $_GET['sku'];
    if(!empty($sku)) {
        // filter char in sku
        $sku = preg_replace("/[^a-zA-Z0-9-\s]/", "", $sku);
 
        // get product by sku
        $product = Mage::getModel('catalog/product')->loadByAttribute('sku', $sku);
 
        if($product != null) {
            header('Location: '. $product->getProductUrl() . "?___store=gb");
        }
    }
} catch (Exception $e) {
    Mage::printException($e);
}
?>
 
# modify .htaccess
RewriteRule ^en/(.*)$ /getProductEn.php?sku=$1 [L]