How to send some specific js, css in express folder?

everyone.

I wanna let front-end js, css files send to client.

So I try to use RegExp to solve it.

Unfortunately, this will make all js (include back-end js) can be browsed by client.

May I focus one folder to send to client @@?

-> config.js

app.get(/(.*)\.(css|js)/i, function (req, res) {
    res.sendfile(__dirname + "/" + req.params[0] + "." + req.params[1], function (err) {
        if (err)
            res.send(404);
    });
});

-> views/ jade in this folder

link(rel='stylesheet', href='../stylesheet/bootstrap-3.2.0-dist/css/bootstrap.min.css')
link(rel='stylesheet', href='../stylesheet/bootstrap-3.2.0-dist/examples/carousel/carousel.css')
link(rel='stylesheet', href='../stylesheet/style.css')

.
.
.

script(src='../stylesheet/jquery-1.11.1/jquery-1.11.1.min.js')
script(src='../stylesheet/bootstrap-3.2.0-dist/js/bootstrap.min.js')