Use the ICICommandSettings interface IsEnabled property to check if a custom command is available, and to either enable or disable a custom command. Refer to Command Settings Interface Properties for an illustration of how this and other ICICommandSettings can be accessed in the Administrator interface.
Signature:
HRESULT IsEnabled([out, retval] VARIANT_BOOL *pVal);
HRESULT IsEnabled([in] VARIANT_BOOL newVal);