Custom Sidebar/Custom Pane

I'm trying to create either in the VBA or the RibbonX of a workbook a sidebar/pane which is similar to how the PivotChart Filter Pane. I'm using Office 2007, and I thought that maybe I could do this via an addition to commandbars, but I cannot remove the added bar from the ribbon. Is there anything specific I could use for this? Or a referenced component, if not an Excel/VBA built-in?

The purpose of the project is that as I go around the workbook selecting various items, I want a summary of what's been selected so far in the sidebar/pane.