There are no ArcSDE command-line tools to import geodatabase XML. Attempting
to mix-n-match geodatabase and ArcSDE concepts will get you into trouble very
quickly. Since the command-line tools are now deprecated, it's probably best to
learn how to tackle this problem using ArcGIS tools exclusively. Using older tools
will make this more difficult (10.0 is now the oldest supported release of ArcGIS,
in "Mature" status [9.3.1 was retired earlier this week]).
- V