Does anyone know of an add-in or other means of adding 'thumbtacks' to the folders in the navigation pane folder view?

I have a long and complex filing system due to my job requirements (COO) and would love to have a way to set those that stay open and those that would only open when I needed to access or file something and then close automatically when I'm done. It would save a ton of time 'thumbing' thru my folders.

If none exists, do you know how to submit a suggestion to MS?

Thanks,
Tom