Backup Windows Files with WinSCP
I use this type of backup for smaller files that may change relatively frequently and are important enough that I want to keep them backed up at a remote location (e.g., bookmarks, email addresses, my budget). I have created a shortcut to the BAT file on my desktop and whenever I change a file, I can just double click on it. The script is interactive in that it prompts you for a password to the remote server, so it can't be automated. If you don't mind storing this password in plain text format on your local computer, then you can add the password to the WinSCP command line and automate when the script runs.
Unfortunately, I don't think it's possible to only replace newer files using this method in WinSCP. So, each file gets replaced every time the script is called regardless of whether it has been modified since the last upload.