I think its a good solution for your problem.
You have to install winscp and the code some files and it will do automaticaly. I used 3 or 4 times. Also you need the key for your SFTP to connect throught it.
Here a link to the guide step by step.
https://winscp.net/eng/docs/guides
Here is a link to the scripting webpage
https://winscp.net/eng/docs/scripting
I recommend you to create an ini file to load all of the characteristics of your ftp connection and then execute an script over this.
It can be launched like that
WinSCP.com /ini=[your ini file] /script=[Your script file(what you want to do when it is connect)]
Hope this helps!.
solved Copy files from SFTP with CMD