I believe this is the kb article you are looking for.
[ScreenOS] Configuration Example on how to redirect Web traffic to a Proxy Server using PBR (Policy-Based Routing)
http://kb.juniper.net/InfoCenter/index?page=content&id=KB24139
I believe this is the kb article you are looking for.
[ScreenOS] Configuration Example on how to redirect Web traffic to a Proxy Server using PBR (Policy-Based Routing)
http://kb.juniper.net/InfoCenter/index?page=content&id=KB24139