Да.Это должно сделать это.
var express = require("express");
var app = express.createServer();
var port = 9090;
app.all(/.*/, function(req, res, next) {
var host = req.header("host");
if (host.match(/^www\..*/i)) {
next();
} else {
res.redirect(301, "http://www." + host);
}
});
app.use(express.static(__dirname + "/public"));
app.listen(port);