How can I get Clicked Line position in OutputWindow?

output window is very useful for tracking source code by double click on the logline included file/line information.

https://msdnshared.blob.core.windows.net/media/TNBlogsFS/BlogFileStorage/blogs_msdn/habibh/WindowsLiveWriter/TheVisualStudioOutputwindowIthasmoretoof_9A42/image_15.png

but file/line with category is not.

OK : System.Diagnostics.Debug.WriteLine("fileline~~")

NOT OK : System.Diagnostics.Debug.WriteLine("fileline~~", category)

so, i want make extension for support category. 

i checked vsix project tutorials and some other source codes.

but i couldn't find how i can get information about position of double clicked.

please help me~