There is no real compatibility issue between the two devices. The express creates a wifi or wired network. If the printer is wifi, it should be able to connect, like any other device would. Otherwise, there may be an ethernet port on the printer. Lastly, if the printer has a USB input, you can plug it into the router via USB.
The router offers up contemporary WIFI security that you turn on, so the compatibilty concern really would be on the printer and not the router.
Lastly, if the printer has a USB input, you can plug it into the router via USB.
It might be useful to remember that if you connect an All-in-One device like the Panasonic to the USB port o the AirPort.......that only the print function will be supported.
Advanced features like copy, scan, maintenance, etc will not be supported when the All-in-One is connected to the USB port on any of the AirPort routers.