Wordpress + Woocommerce custom billing fields

Hello guys, i am owning a webshop, and i create orders manually from admin panel. I need to add extra fields to billing info and show it in invoice via Woocommerce pdf plugin.

Originally i need 2 extra fields to be able to input here (under Registracija column): 

How can i add extra VAT and Company Code fields to this “Registracija:” form ,which originally is Billing address? I don’t need auto VAT checking. And i can’t locate any info in regards this in internet…