OPC Force new address

[PhpMadman]

Hi.

 

I'm creating a special site for some of our customers. Registered customers only.

I create accounts for them, and then they add product to cart.

 

And then in Checkout I want to force that the billing address is the one I added when I registered the account.

Should be something simple as just getting the lowest id for that customer I guess.

But the delivery address, should and must always be submitted as a new address.

 

I started by hiding Delivery / Billing address boxes.

Then there is only the add address button, but that redirects to a new page. I want the customers to be able to add the address directly in the OPC, just as new / guest customers do.

And then that address should be auto selected as delivery address.

 

Any ideas how to accomplish this in the simplest way?

Module, override, theme changes?