Use existing .net Membership authentication for FTP server in IIS7.0

Hi,

I have a asp.net website running on ISS7.0 as the default website with .netFramework v4.0. We want to stand up a ftp server (not on the website directory, but on a seperate directory). But we want to use username and passwords from the asp.net site to log into the ftp server to eleminate maintaining seperate username and password list. We are planning to create a seperate role in our website to allow the users who can use the ftp to upload and download. I have looked into 'Configuring FTP with .NET Membership Authentication in IIS 7' article at the following link

http://www.iis.net/learn/publish/using-the-ftp-service/configuring-ftp-with-net-membership-authentication-in-iis-7

It looks like, this article is about making a website directory as ftp server. How do I make a folder other than the website directory work as ftp with .net Membership authentication in IIS7.0.

Any help is greatly appreciated!

Thanks,

Ana