I would like to pass requests from first.com and second.com to a single server is this possible?

so basically what I am thinking is to run

first.com in port 8080
and
second.com to 8081

in the dns I only put the server ip..
first.com server.ip
second.com server.ip

now I need to run something on port 80 right then just pass the requests to the ports...

I only have access to a single ip and server...