Z-wave slave/relay setup to extend range to another building

Hello,

I got a external building that I hooked up a GE z-wave lightswitch to. If the door to the building is open, my z-wave setup can talk to the lightswitch. However with the door closed, it cannot.

The building has a steel door with aluminum siding, besides the distance, is the hurdle I have to overcome.

I do have wifi out in the building. Is it possible to route the z-wave traffic/commands over wifi to another device inside the building? Looking at making a slave/relay device. Happy to buy another rasberrypi3 and Aeon stick if I have too.

I don't think adding another z-wave device (like a plug) will be enough to punch through the build's exterior.

Looking for suggestions.

Thank you,
CM