To find current HWND of application window you are interested in, you can enumareate windows using EnumWindows
:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms633497%28v=vs.85%29.aspx
or maybe easier is to use FindWindow
, if you know its name/class:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms633499%28v=vs.85%29.aspx
you can also use GetWindow
to iterate windows:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms633515%28v=vs.85%29.aspx
...lots of possibilities