Hi my name is Shaw aka Dr.Fix-It , Your online expert ready to assist you...
Your clippings are backed up on your Amazon account and can be found at http://kindle.amazon.com
If you deleted the text file from you 'my documents' folder, if have the file on your computer you can simply drag it into your 'my documents' folder on your Kindle... Otherwise can open notepad on your computer, copy the highlights save on your Amazon account from the http://kindle.amazon.com link provided and save the file as clippings.txt
Let me know if that makes sense and how it goes with a reply, thanks & happy Holidays