title: How can I control the size and position of a new process Window from a WinForms app?
body: <p>My WinForms app uses <code>Process.Start()</code> to open files in their native app. I want to split the screen in half, showing my WinForms app on one half and the new process on the other. I know I can use <code>Process.MainWindowHandle</code> to get the window handle, but how can I set its size and position? </p>
  
  <p>I imagine I have have to use some kind of Windows API, but which one and how? Since this is not really "in my wheelhouse", I am unsure of whether (and how) I need to use different APIs on 64bit Windows.</p>