[squid-users] rewrite content and url

is there a way to replace content on the fly? and/or url?

for instance:

content:
user goes to website and at one point he reaches a site that has
certain content, i want to rewrite that content something else

url:
user goes to specific url and instead of sending user to that url, i'd
rewrite url and send user to different url?

thanks in advance

-- 
http://alexus.org/