For that I would most likely skip the schematic step and use automation to place the desired objects on the board directly. Such as placing padstacks as above, then connecting them with traces and planes as needed by way of automation commands. I don't have anything quite like that, but it's definitely possible to place padstacks and traces to simulate pins and connections. You can use Net0 for all these connections so that you don't get as many DRC errrors.
And, not to be snide, but I'd also do whatever I could to avoid placing coupons on a design. I'm sure you have a good reason for it, but if it's possible to avoid doing so, I would. It's a lot of work, time, and effort to do something the board fabrication shop is already geared up to do