Code:
if (Splitter[0] == "/command" && Client.AccountStatus >= 8)
Essentially you just add something like "&& Client.AccountStatus >= 8" to the end of the command, since 8 and 9 are GM and PM flags.
You may have to modify it to work with your source. =D
==--
&& Client.AccountStatus >= 8 : GMs + PMs can use
&& Client.AccountStatus == 8 : ONLY GMs can use
&& Client.AccountStatus == 9 : ONLY PMs can use
--==