Where is the command line interface? Please help

I have a virtual private server with GoDaddy that uses the Parallels Plesk 9.3 panel. I am trying to increase the maximum number of entries in one person's whitelist, and I have found the command to do this, but I cannot access the command prompt/command line interface anywhere.

I have Googled this topic for two hours, contacted GoDaddy, and searched this forum but have been unable to locate the answer. All I see are things like "Log into the root and type in this command", but when I log into Plesk, there is nowhere for me to type in a command; there are just icons to click on, and none of them say anything about a command line interface. As you can probably tell from my post, I am no network administrator, so please bear with me.

Can someone please help me locate the command line interface so I can enter the necessary command? Thank you SO much.

 

Maybe ask in the Plesk Products Discussion forum?

 

joevt, thank you for the link! I could not find a thread for Plesk/Unix eariler (yesterday was my first time visiting the forums on this site) but thanks to you, now I have. I've posted my question there. You're great for helping me!