Could you correct it by yourself using a CASE statement?
Think on why would it give an "Invalid length parameter passed to the RIGHT function."
Try an post back the code to share the solution with others or check where are you having problems.
Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?
How to post data/code on a forum to get the best help: Option 1 / Option 2