I am not that familiar with FrontPage, but it is possible that FrontPage will create the sub-directory on your host automatically when uploading the site.
If not, then you can create the sub-directory manually using an FTP client or via SSH. You would create the sub-directory in the root directory that has the same name as your domain.
For example; If your domain is greenaissance.com, when you access your host with an FTP client you will see a directory called greenaissance.com, you would create the sub-directory in this root directory. Something like greenaissance.com/subdirectory
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