revrob - 4:24 pm on Sep 29, 2012 (gmt 0)
Thanks for all the replies. I think I've got it. So far the result of having the original temporary redirect with redundant bits in place has been that the bad bingbot IPs have made far fewer visits but then it is the weekend. I'll monitor progress over a couple of weekdays then try out various of the corrected alternatives above.
Once again many thanks.