Extra CSS classes for sidebar

Custom Sidebars Pro works perfectly for WordPress site! It's truly a powerful tool for us.

I need to customize the sidebar to make it sticky. But this sticky CSS won't apply to all sidebars, just couple new sidebar added by "Custom Sidebars Pro". To do so, I need some extra CSS classes for these newly added sidebars.

Is there a way to so? I notice I can add a wrapper to widgets and titles, but I need wrapper or classes to the sidebar. The solution could be either plugin or some codex, it's fine to me.