Client interface to an FTP site is totally dependent on the client software. You could set up a web page that contains links to your FTP server. Most web browsers, IIRC, will render html files if you click on them from within an FTP site, but there's not really any way to get the FTP client to go there automatically, unless you publish your link as ftp://ftp.example.com/index.html -- that is, as a link directly to the html file and not a directory.