Build a plugin for nop commerce open cart software

I would like to have a functionality where customer will be restricted to use no more than X reward points for a purchase of certain amount. This is to restrict the customer from not using all reward points at once, as sometimes for marketing purposes, most reward points can be given for free. This would be useful for scenarios such as "Invite your friend and earn 250 reward points. USE 50% OF YOUR REWARD POINTS TO PAY FOR YOUR CART" Also If we could add expiration time for reward points that the reward points will expire if you don't redeem within x months or so. In short when a customer buys for say 2100, only then he would be able to use his/her reward points. All this should be done for a store running on nop commerce 3.7