Frank,
Assuming that the lamp is double-insulated (class II) and doesn't require a ground, then the standard plug would be type
CEE 7-XVI {click for picture}.
If by any chance the lamp needs to be grounded, then it would be the standard German "Schuko" connector, type
CEE 7-VII . This has ground contacts on the side of the plug.
Both plugs are non-polarized, and I believe that to conform to German safety regulations the cord must be double-insulated (i.e. you couldn't use American SPT type cord). This might not apply to a private one-of deal -- I'm not sure.
I've also found a U.S. supplier for foreign cords here:
www.intlcordsets.com Standard wall outlets are 220 or 230V with one pole grounded (standard distribution is 220/380 or 230/400V wye).
