Linking Coupon to a Group of Users

I always give my registered customers a coupon code for free shipping for 4 days after Thanksgiving to encourage them to shop early.  Invariably a number of them forget to  enter the code before submitting the order and ask us to do it retroactively.  Always a bit of a pain, with the new CVV requirements, modifying an order after submission but before capture has become a much more labor intensive process.  It is great that we can link a store credit coupon, etc to an individual customer. Is there a way to do it for all customers who are registered at the time the code is established?  What a time saver that would be for both staff and our customers!!