Develop Addin for Excel

Hi,

I am trying to develop a simple addin for Excel which will talk to server in back end and give the response to the user.

I am able to develop this com addin using Visual Studio 2012 and it works fine for Excel on Windows.

I need to do the same for Excel on Mac OSX.

Is there a way to port the same com addin to work for Mac or how can we develop the addins to work on Mac.

Kindly let me know your inputs.

Thanks

Manu