Configuration issues....I am confused

Hey anyone ...help me out.

I have chat installed on my site (laboratory.4path.com) and I have some of the configuration put in place. I have it set up to be on certain pages and pop up in the lower right hand corner.

Here is where I am confused. Perhaps you can help.

What I want to do: Have a chat function for my clients to be able to contact someone on my staff to ask questions.

1. It has to be private...only one outside user at a time. This is to keep the conversation private.
2. How do I get it set up so that anyone in my office can "pick up" the chat and work on it? how do I configure those users?

Thanks.

Steve