Hi Rudy,

>>Somehow, when I open MOI, press ALT+D, nothing will happen. The custom distance will not come up.

Make sure, the shortcut Alt+D exists! Open options dialog window; in the Shortcut keys section there should be:

   Alt+D     CustomDistance

or you can set up the different shortcut if you want.
When you unzip a custom command into the command folder, the shortcut isn't created automatically for this new command. You must set it up manually first.

Petr