Need help with replacing string in MS DOS Command line

Hi,

I would need to know how I can replace a string value that is stored in %servername% from the string in %taskname%?

set taskname=%taskname:%%servername%%\=%
(does not work)

Here is an example what is being achieved

taskname = bnp-s-3432\Restart server
servername = bnp-s-3432

So the result should be only "Restart server" (without quotes).

Regards,
Dejan