I agree that you only need your own signature(s) in your logbook. I have a US logbook and it only has my signatures in it. My UK licence and IMC rating (I hope you didn't lose them) has the annual sign off sheet. So I think that all you need to do is print out the excel logbook. Sign each page and then take it with your licence to whoever is doing your renewal.
You didn't say what other signatures you had...maybe sign off for 1st solo etc? These may not matter (apart from sentimental value) as you have your licence.
You could of course buy a new logbook and spend time writing all the flights in it by hand and signing each page but this might take some time.
I feel for you....but the daily mail isnt the way!
Far better to send them on a three week 'life experience' to Africa or somewhere else nice at the taxpayers expense so they can reflect on the error of their ways!!!!