Hosting Multiple website with same ip but different subdomain

Recently, I had setup 2 different computer to host different websites.

192.168.xxx.xx4:80 --> 223.xxx.xxx.xxx:80 -->http://www.abd.com/ http://abd.com/
192.168.xxx.xx4:8124 --> 223.xxx.xxx.xxx:8090 --> http://123.abd.com/
192.168.xxx.xx2:80 --> 223.xxx.xxx.xxx:8230 --> http://345.abd.com/

It is easy for me to use router's port forwarding to link the Lan IP and Wan IP. However, when it comes to DNS, I have no idea how to set it. I had researched that SRV record / virtual host might help me, but there are not much documentation I can find. Can someone help me? Thanks