[Plugin: Redirection] Redirect a Search

Hi

I’m tring to redirect a search using the plugin Redirection in my wordpress blog but is not working

Ex: /s=coupon walmart to http://myblog.com/couponwalmart

Does anyone know how to fix this?

http://wordpress.org/extend/plugins/redirection/