Route the static over wifi?

As is: the modem hands out DHCP to various devices on WiFi, and routes my static IP to a server plugged direct into the modem. Everything is working fine, except:

I want to move the server that handles the traffic for my static IP, far away from the modem.

I do not want to run the blue wire.

To be: everything remains as it is for the WiFi devices enjoying DHCP, my static IP is also routed --using WiFi-- to my server located elsewhere.

I guess that's clear enough? I am hoping there's some sort of config, everything I found starts with "plug the server into the modem".

Thanks!