My name is Lizzy and I’m from the support team at Shopify.
There isn't a way to have the shipping address in an order affected by a discount code. However you may have a few options depending on how your fulfillment team receives orders.
If they see the entire order page, the discount, and its title will appear there. This means that you can let your team know that any order with this specific code should be put aside instead of shipped.
If your team are just receiving the order items and shipping address, you could advise your family and friends to either enter a fake address that you provide to them, or the address of your fulfillment center. Then again, you can let your team know that any address with the predetermined fake address or your own address should be put aside.
There are also apps that offer a pick up shipping option, you can find those here. Keep in mind though, that including one of these would make the option of collection appear to any customer using your store. Are you just planning on setting this up for people you know, or are you hoping to expand a collection offer to other customers in future?
Please feel free to share any questions you have about the options I've explained here!