Dnsmasq hostnames on a public domain

I have an OpenWRT/LEDE router with Dnsmasq. I currently have a local domain (something.lan) that is appended to DHCP names, so I can access devices on my network just by connecting to, let's say, computer.something.lan. Neat. Recently, I have finally gotten native IPv6 connection. This means I can now reach all my IPv6 capable devices from the internet. I have a domain name (something.tld) and I want to use it for AAA records to DHCP names. Something like setting lan.something.tld NS record to routers IPv6 address and then letting Dnsmasq act as a nameserver (somehow)? Then I would be able to use computer.lan.something.tld in both my local network and the internet. Is something like this possible? Of course I can just set the AAAA records manually, but I would like it to be automatic.