How do I temporarily remove a contact from a group?

I have a "jokes" group. When I receive a message from someone in the group that I want to send to the others, I use the sidebar to change the properties of the group to delete that person so that they won't be getting the message back. Once sent I go in to "write", scroll down to the group, hit properties and add the person back on. I use the sidebar because I may send the message to others not in the group. Also, when I change the group, it disappears from the side bar. I have to save the message, close it, pick it up again in "drafts" whereupon the group now appears in the sidebar listing. Is there a better way to do all of this?