It can't be done. I don't think you realize that in a URL, the port is specified by the scheme. For example, and HTTP connection defaults to port 80, HTTPS to port 443, FTP to port 21, etc and you override the defaults by explicitly specifying the port.
So in order to do what you want, you will have to do some hacking to get your computer to think "nas://hostname/" means to connect to port 1111 at hostname. Your barking up the wrong tree thinking you can do so using DNS.