Imagine this:
I have a EC keypar Ks and Kp. (secret and public).

Now I have a system with access card for customers. I want them to be able to refill the cards. Each card contains a number, lets say "1013853254", which is denoted "n".

By publishing Kp, a customer should be able to combine Kp and n, in such a way he gains a public key Kp(1013853254).
If a customer sends Money to the associated adress of this public key Kp(1013853254), then the funds
should be spendable by combining Ks with n in such a way I gain Ks(1013853254).

How is this possible with lets say EC primitives?