Open an MFC dialog based application using the Windows context menu Send To command

It has been a long time since school, and I am beating my head against the wall trying to figure out how to do this. I am writing an MFC program using Visual Studio 2008. I want to be able to right click on a file and send it to the program using the Windows Explorer Context menu Send To menu. Could be any type of file, but for now we can just say a text file. The send To command needs to open the program and process the file.

I remember that it will involve InitInstance and the GetCommandLine function, but I am drawing a blank here.