ASP.Net reverse proxy, what to do with external resources?

I'm currently working on a concept for a reverse proxy to basically relay responses and requests between the user and an otherwise invisible website. So basically the user goes to a site, let's开发者_如何学Go say www.myproxyportal.com, where it is possible to access a website (in an iframe) in the webserver's intranet which isn't made public (for example internal.myproxyportal.com).

I've been working on a solution where I translate request objects to the desired location and return that response to the website. Works great, except for stuff like CSS links, IMG's, etc. I can do the translation of course, but then the link would go to internal.myproxyportal.com/css/style.css and this will never work from the outside.

How to approach such a thing?

Are there any out of the box solutions maybe?

EDIT: I found this, which is very similar to what I have written so far, but it also lacks support for external images, css, javascript, etc.

You can change settings in IIS to route all requests through ASP.NET pipeline, not just .aspx pages. Then simply create an HttpHandler to handle those in your proxy.

By default, IIS doesn't run "static" content requests through ASP.NET engine.

Apache has a pretty slick reverse proxy built-in, I use it extensively.

See more here: http://www.apachetutor.org/admin/reverseproxies