RE330 Wired Device

My parents have a CCTV system which only uses wired internet connections. I'm hoping that I can use the RE330 'backwards' and instead of using the ethernet port to connect to a router as a Access Point, that I can plug the CCTV into the RE330 and use it to wirelessly connect to the wireless router in the other part of the house.

Anyone with experience of doing this? Can it be done? Been reading the User Manual and a few other bits online and can't see the steps to take anywhere to 'reverse' the default funtion of the ethernet port.

Thanks in advance