Mod_rewrite help

I’m working on a site where the URL vars have shifted because they migrated their database. For example “www.website.com/pages/search_details?tourid=ETTD000001” changed to “www.website.com/pages/search_details?tourid=ETWT00000001”. These will be eliminated over tima as the id’s are always incrimenting and they remove the old ones so i want to setup a mod_rewrite. However mod_rewrite hates me and will not cooperate. I have tried:

RewriteEngine on 
RewriteRule ^/search_details?tourid=ETTD000001$ /search_details?tourid=ETWT00000001 [R,NC,L]

and putting that in a “.htaccess” in the pages folder. doesn’t even try.

Any ideas?

JJ