After re-reading your post I realized that I was thinking about the Web Designer product.  Website maker is online software so I really can't give you a precise answer.  If you can access your site via ftp you would have received a email with instructions something like this when you purchased the product:

Your FTP access details
The following FTP details must be entered into your homepage software/ FTP software in order to gain access to your web space:
 
FTP-Server (Host):           ftp.magix-online.com
Login / username:            Your email address at MAGIX
Password:                         Your chosen password

the above information would be entered into your ftp application, you would select the files that you want to ftp establish the connection and that is pretty much it.  I have some personal doubts as to if an application run on-line from a Magix server would have the ability to use file transer protocol because if the site is designed and published on-line there would be little need to transfer files via ftp.  Unfortunately you did not mention in your follow up post what you are trying to do, you just said you want to do something other than drag and drop.