I'm guessing that you are trying to get as close to the keyboard as possible so that key inputs are not intecepted by any other application, am I right?
Normally applications get keystrokes directly from OS. The closest that you can get to windows is using Win32. If you have an edit-box selected, then keyboard inputs will go directly to the edit-boxes WndProc.
If you want to get closer to the keyboard so that even your OS doesn't read it as a keyboard, you'll need to create your own driver for the keyboard. This has the disadvantage that your client can only use keyboards supported by your driver.
How do I explain...the application I wrote has the keyboard cooperation level set at foreground non exclusive. I am wondering if another application set at background exclusive/non exclusive will my foreground application recieve input as well as the background does if it is polling? SO that really I believe they will both take input from the keyboard: the same input and when background aplication shuts down my application will keep recieving input keyboard too.