We document Corona’s Windows Phone 8 support here…
  https://docs.coronalabs.com/daily/coronacards/wp8/index.html
We do not support WP8 builds via the Corona Simulator or Corona Enterprise.
We only support WP8 via CoronaCards, which is a Visual Studio extension.
Our Visual Studio extension provides our WP8 libraries and WP8 Silverlight project templates for C# and VB.NET. The project templates generate a Microsoft standard WP8 Silverlight project with Corona’s library framework already referenced/linked and a working Hello World Lua project already bundled into it. In my opinion, it’s pretty easy to use.
Just note that WP8 CoronaCards only supports a subset of our Lua APIs compared to what’s supported by Corona Simulator or Enterprise builds. We document what Lua APIs are supported via the link below. Note that our Lua network and socket libraries are supported.  Unfortunately, plugins are not supported.
  https://docs.coronalabs.com/daily/coronacards/wp8/support.html
So, any features not supported by Corona you’ll have to implement yourself in .NET. But the good news is that we have a pretty nice Lua/.NET bridging/communications interface. Have a look here…
  https://docs.coronalabs.com/daily/coronacards/wp8/communication.html
I hope this helps!