How to build an ASP.NET Proxy Site

I want to build a proxy site that renders any URL.

Given an url, I need to replace all html links, css links and js urls from

href="/original.htm"

to

href="http://www.myproxy.com开发者_StackOverflow中文版/get?www.original.com/original.htm"

sort of.

How can I do? is there a ready-to-use framework? I use ASP.NET and C#.

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http://www.codeproject.com/KB/aspnet/asproxy.aspx