Allow filter woocommerce orders by order meta fields

Hi fantastic plugin, we only came across this at the weekend and will be so useful for a lot of our sites. One thing though we use a plugin called order delivery date by tyche softwares and they add extra post meta to the orders to allow for a delivery date to be added, also uses shipping fields of whether it is local pickup or delivery so would be handy if we could filter the orders by these fields, is there a hook we can add these into? I realise that this is a free plugin so any guidance would be helpful.