Private domain using pi-hole without pi-hole as DHCP server?

Hi,

Under Apple Server, there is a DNS server that allows me to associate and IP address to a private, internal DNS (i.e. mydomain.lan). How do I recreate this using Pi-Hole without enabling the Pi-Hole's DHCP server?

Is it something that I can do using a configuration file, if there is no GUI?

Edit /etc/hosts