int pascal WinAddChild(HWND hWnd, HWND hChild)

  This function adds a child window to another window. WinAddChild()
basically adds the child window to a linked list of child windows
which hWnd maintains. When you create a window using one of the
creation functions, the parent is specified as the first argument; in
this case, the window system automatically creates the parent-child
link. WinAddChild should be used when you want to alter that initial
link.

Parameters
  hWnd is the handle of the window which you want to add the child to.
  hChild is the handle of the child window which you want added.

Returns
  Nothing.