Installing hotspot on RB and the ISP is also hotspot

Hi everybody
i ve RB2011UiAS-2HnD and i want to do this for my own reasons :
receive the internet from a link which provide the internet service with hotspot
then install a hotspot on my RB so when a user connected to it he has to pass through 2 hotspots; mine and that from my ISP , the problem is whenever any user connected to the hotspot of my ISP all the users can access it without authentication , i need all the users have 2 usernames and 2 passwords one to access my RB and the 2nd to access the ISP hotspot and they r isolated from each other, can i do that ?