I've made an alias to a folder on my external hard drive and added it to Finder's sidebar. Whenever I eject the external hard drive the newly added item to the sidebar disappears and doesn't reappear when the hard drive is plugged back in. I want it to disappear when the external hard drive isn't connected and REAPPEAR when the external hard drive IS connected. How can this be done? Thanks!
Try creating an alias on the desktop or a folder, and then either copying that or creating an alias to it in Finder's sidebar (that is, an alias to an alias).