LC_Page_Admin_Order_Edit.php
function setMultipleItemTo(&$objFormParam){

     /*
    * フォームの配送先ごとの配列を生成

    */
    // 受注商品の数量を変更
    $arrDest = array();
     foreach ($objFormParam->getValue('product_class_id') as $n => $order_product_class_id) {
        $arrDest['quantity'][$n] = 0;
    }
    foreach ($arrQuantity as $product_class_id => $quantity) {
        foreach ($objFormParam->getValue('product_class_id') as $n => $order_product_class_id) {
            if ($product_class_id == $order_product_class_id) {
                $arrDest['quantity'][$n] = $quantity;
            }
        }
    }
    $objFormParam->setParam($arrDest);
}