How to make blog index appear only as login page

Hi there,

For the website I am designing I have used wordpress to customise my own blog with all my own css, html etc. This means that I have wordpress installed to an arbitary /blog directory, but it is still visible publicly when you simply visit /blog. This is not what I want as I don’t want users to view the blogs via the wordpress site but I do need to be able to access the wordpress admin control panel.
So what I need to do is: make it so that /blog simply redirects to the wp login page so the only purpose for /blog is to login when you want to manage the blog.

Thanks for any help you can give.