these are no "DOS commands"...
http://www.microsoft.com/resources/docu ... x?mfr=true
DISKPART ist a commandline program and is also scriptable.
so, the "correct" way would be to write a script for DISKPART,
and run "diskpart.exe" via RunProgram with the script's filename as parameter.
there should be also a way to hide a partition via API directly,
because somehow DISKPART itself accesses this OS-functionality.
additionally, this is playful messin'round with internals, you know that.
only nice to know and for fun, without any useful application.
oh... and have a nice day.