If the printer is working great with your Mac computer.. not MAC btw as that is Network Hardware Address.
Then there is no need to use the 8 digit pin for the router which is how to get it working over wifi.
This is called WPS.. and the airport router does not work well by that method.
I need to ask some questions.
Is the printer connected by wireless or ethernet to the router?
Assuming it is already connected since you stated it is working.
When you look at the airport router now in your airport utility on the Mac .. and if it is connected by wifi then you will see a list of wifi clients.
e.g. Click the icon of the airport.. and you will see a list of wireless clients..
They can be listed by name or IPaddress or MAC address (Network not Mac computer). See below where you can see the MAC address is listed as Hardware Address. If you don't know which one is the printer.. then please use the printer display or print out the printer test page which will tell you IP address and MAC address etc.
You can then use that info on the PC to configure the printer port.
