To change the default mouse cursor image in CDE -- and every other window
manager -- use the command "/usr/openwin/bin/xsetroot -cursor", and provide
a path to the cursor bitmap and the cursor mask bitmap you want to use.

From the xsetroot man page:

     -cursor cursorfile maskfile
          This lets you change the pointer cursor to whatever you
          want  when the pointer cursor is outside of any window.
          Cursor and mask files are  bitmaps  (little  pictures),
          and  can be made with the bitmap(1) program.  You prob-
          ably want the mask file to be all black until  you  get
          used to the way masks work.

Note that in CDE and other window managers, individual applications can
override the default mouse cursor image with their own images.

You can use the /usr/openwin/bin/bitmap application to draw your own cursor
and cursor mask bitmaps.  See the bitmap man page for more information
about this application.

For example:
xsetroot -cursor /usr/openwin/share/src/xview/examples/dnd/arrow.bm
/usr/openwin
/share/src/xview/examples/dnd/arrow_mask.bm