Opening file in my OS X Unity App

Hello
I’m developing a cross platform application able to open and edit its own kind of files.
On Windows, it was quite easy to open files with my app using the arguments of command line.
On IOS, well it finally worked editing the Info.plist and the AppController.mm in Xcode.
On OS X, well I don’t know how to do it. I modified the Info.plist file inside the packet of my app… but Unity already compiled all the files, so I can’t access to AppController.mm nor to AppDelegate.m to handle the file. Moreover the AppControler file inside the Unity packet seems to be exclusively used for IOS building.
Would you see a way to do it ?
Thank you for your answers.

Hi,
You have access to all file i/o C# .NET functions directly in script, so actually you maybe you don’t need any specific native code.
If really you need something specific, you can write a native Mac OS X plugin. Check the Unity doc for that.

Well in fact I’d like that Os X sees my App as able to open my kind of file. And be able to do Open With my app from the Finder…
But thanks, I’m going to have a look on the Mac OS X native plugin writing

OS X native plugin writing doesn’t seem to be able to do that… It only allows the Unity program to call native OS X functions, it won’t change the fact I have no way to implements the mandatory methods in AppDelegate to handle the files.
Here is what I found on how to create an OS X app which can do what I want :

And I really don’t see how to do it with a Unity app.