See upstream project to run DNS Server locally on your computer for Wii & DS. I use this project to import local DNS entries to Pi-hole.
On the server running Pi-hole, run either of these commands:
sudo curl https://raw.githubusercontent.com/robcmo/DNS-Server/master/dns_zones-hosts-verified.txt -o /etc/pihole/custom.list -a
RiiConnect24 domains will be listed on Pi-hole webpage menu under "Local DNS Records".