Magento Get custom attribute value in admin Invoice Grid

Question

I want to display my custom attribute value in magento admin invoice grid in "Item Invoiced" section

app/code/core/mage/AdminHtml/Block/sales/order/Invoice/View/Items.php

its generated via

 public function getOrder()
    {
        return $this->getInvoice()->getOrder();
    }

now how should i place my own attribute in this grid for expample weight attibute as a separate column?