Woocommerce & Advanced Custom Fileds

Hi,
A simple issue, I’m trying to populate the checkout form of woocommerce with filed create width Advanced Custom filed.
E.G.: I have a php page that register a private costumer data($name, $surname, …) and save the data in a post type group created with Advanced Custom filed. Saved the costumer datas, it redirect the costumer to the single product page, clicked on buy the costumer will be redirect to checkout. Here I will that the field are not blank, but that woocommerce use the field saved.
Otherthing passing frought the php page to the single product give a error of security? How can I resolve it?
I trying using WooCommerce Checkout Manager, but isn’t right.
May someone help me?
Site http://www.serviziosalute.it
Thanks for the help.