BazB was right in his answer to your previous question. CGI works over HTTP, which is a completely different protocol from FTP. You can upload files through HTTP, but it's very different from uploading files through FTP.

If you were to explain what you were trying to accomplish, not how you think you might want to accomplish it, it would be easier to give you suggestions on how you could accomplish it. Something like "I want a user to be able to upload a small personal image to display on a web page without having to have an account on the web server" would be appropriate.