Position window

        Entry:
          AX = 1023h
          BX = segment of object handle for parent window within which to
               Position the window (0 = full screen)
          ES = segment of object handle for window to be positioned
          DL = bit flags
               Bits 0,1: horizontal position
                  00 = current
                  01 = center
                  10 = left
                  11 = right
               Bits 2,3: vertical position
                  00 = current
                  01 = center
                  10 = top
                  11 = bottom
               Bit 4: don't redraw screen if set
               Bits 5-7 not used
          CH = number of columns to offset from position specified by DL
          CL = number of rows to offset from position specified by DL

        Return:
          Nothing