change class name of a dialog

[dima2]

hi,

actually what I'm trying to do is detect if applicationA is running and end it.
From applicationB I need to call FindWindow providing the class name of the main window of applicationA, get it's handle and post a WM_DESTROY message.

Therefore I need to register my class with a specific name.
How can I change the name of the class that MFC generated?
and where should this be done? in OnInitDialog, OnInitInstance...???

thanks for your help