DNS Mapping to Internal Server

I am using the peplink balance 210 as the authoritative DNS Name Server. I’m interested in having multiple A records using the same public IP and being able to map, by DNS, to different internal servers. I can see the peplink supports NAT Port Mapping for a WAN Public IP to an internal server but couldn’t find a way to map a specific DNS match to an internal server.

Public Static IP / Host / Internal LAN Server → foo.com → (Server A) → bar.com → (Server B)

Is it possible to create mappings to internal server IPs by the DNS vs port mappings?

My goal is to minimize Public IP usage. I know that I could achieve this using Apache and Url Rewriting like below, but is there a way the peplink balance could do this? (Port 80) → (Apache - foo.com - Port 80) → (Port 80) → (Apache - bar.com - Port 80) →