How do I receive an http request with a Node.js server and then pass that request along to another server?

There's a lot going on here so I'll simplify this into a pseudo example. Forget about security and whatnot for a minute here. The point is to understand the functionality.

Let's say I'm running a local web server with node.js to dev a website. In the website, the user should be able to create a new account. The account information will be submitted via ajax to the node server. I then need the node server to take the incoming request and pass it along to another server that gives me access to a database. CouchDB, for example.

So here's a pseudo example of what I'd like to happen.

In the client's browser:

$.ajax({
  url: './database_stuff/whatever', // points to the node web server
  method: 'POST',
  data: {name: 'Billy', age: 24}
});

In the Node web server:

var http     = require('http'),
    dbServer = 'http://127.0.0.1:5984/database_url';

http.createServer(function (req, res) {
  /* figure out that we need to access the database then... */

  // magically pass the request on to the db server
  http.magicPassAlongMethod(req, dbServer, function (dbResponse) {

    // pass the db server's response back to the client
    dbResponse.on('data', function (chunk) {
      res.end(chunk);
    });
  })
}).listen(8888);

Make sense? Basically what's the best way to pass the original request along to another server and then pass the response back to the client?