Enable Internet Connection after manual installing the piratebox

Hello,
i am a student and i built with my friend a piratebox for my class. Now we have two wifi signals in our classroom. One from the piratebox and another one which connects us to the web. Can anyone explain me if it is possible to share with the piratebox also the connection to the web from an ethernet cable ...like a normal hotspot...and use the piratebox too? :)

Thank you for your answer :)