Alternate bill to set up - can the entity be a 'ship to' under a cus

is there a way to set up an "alternate bill to" without setting that entity up first as its own standalone customer.

We were really hoping to be able to use a ship to that has been set up already to be an alternate bill to.

meaning

customer a has a ship to address b

we would like to set up an alternate bill to under customer a of the ship to address b without having to set up ship to address b as its own customer.

thoughts?