Simple project - Wifi extended from captive portal

HI, I am looking at getting a wifi setup at holiday place, but I need to get round the captive portal. When I say get round, there is no password or username, it is a simple tick box (Auth) based on MAC address I assume. I have purchased the kit and it all works fine, when I set it up at home and bounce the signal when I have a user name and password for SSID. So need to get round captive portal, to allow free captive portal to be re-transmitted.
Please quote WIFI007 on responding