Add referred data to order confirmation email in Magento

Hello, I need help with a quick, simple addition that I would like to integrate into Magento shopping cart. When a new order is made, Magento sends out an order confirmation email to the admin and the customer. I would like this email to include referrer data that has already been captured, when sent to admin ONLY. Or, if this is easier, just send this as a separate email to admin only. The referrer data is captured when a user enters the site via JS/php and the variables will be provided to you. Please let me know how you would implement this and if it would include any mods to the Magento core files - i.e, is it upgrade-proof? Let me know if any questions! Best regards