Command risk

Dears,

Please note I am trying to set command risk on a host, where the execution of an nslookup in CMD; I tried *nslookup*, nlsookup, *cmd.exe nslookup*, *cmd.exe-nslookup*; without succeeding.

What is the right format to specify a certain command in CMD?

Also is there a directory of the available commands?
Best regards,

Georgio