Share wifi connection from macbook to airport express I'm trying to do the following setup:

Internet modem/router -> (wifi)  -> Macbook -> (ethernet) -> Airport express ->(wifi) ->  various devices.

Is it possible to share internet from a MB to an airport express through ethernet?

My MB is a MacbookPro retina from Mid 2012

As to why i'm doing this: I don't have access to the internet modem ( can't plug anything to it), so i'm trying to spread wifi to the rest of my apartment any ways I can. Any other ideas are welcome
Go to System Preferences -> Sharing.
Enable Internet Sharing.
Set Share your connection from to Wi-Fi
set the To Computers using to  Ethernet.
Connect the ethernet cable from Macbook to your airport's Ethernet WAN port (Dotted circle).
That's it.