Split content into a subdomain

Hi,
I have a standard Kirby setup, which has a few directories:

https://project.com/ford
https://project.com/arthur
https://project.com/zaphod

I now need to split out one of these into a subdomain, e.g.

https://zaphod.project.com

I would like this still to be managed by the Kirby installation at project.com, and also have any directories within still work, e.g.

https://zaphod.project.com/section/page-1

should show the content from

https://project.com/zaphod/section/page-1

What would be my best approach for achieving this? Thanks for any help

Basic setup: Quicktip: Serving a page on its own domain | Kirby CMS