void pascal WinClientRectToScreen(HWND hWnd, LPRECT lpRect)

  This function transforms a set of rectangular coordinates expressed
in client coordinates into a corresponding rectangle expressed in
screen coordinates. The client coordinates are relative to the
upper-left corner of a window's client area, and the screen
coordinates are relative to the upper-left corner of the screen.

Parameters
  hWnd is the handle of the window whose client rectangle we should use.
  lpRect contains the client coordinates. After this function is done,
   it will contain the screen coordinates.

Returns
  Nothing.