int pascal WinBltRect(HWND hWnd, LPRECT rDest, LPRECT rSrc)

 This function copies the screen data which is enclosed by rectangle
rSrc to the screen area specified by rectangle rDest. In graphical
windowing systems, this operation is often referred to as "blitting".
Please be aware that no clipping is performed by this function. It is
a fast way to copy character cells from one location to another.

Parameters
  hWnd is a handle to a window.
  rSrc and rDest are pointers to RECT structures which specifiy the
   source and destination rectangles respectively.

Returns
  TRUE if the blitting was done, FALSE if not..