EM_GETHANDLE

  Retrieves the far address of the an edit control's text buffer.

Parameters
  wParam is not used.
  lParam is a pointer to a user-supplied far pointer to a holder for the text buffer.

Example
  char far *szHandle;
  SendMessage(hEdit, EM_GETHANDLE, 0, (DWORD) (char far **)
&szHandle);