Re: trace the download progress?
I recommend you use WinSCP .NET assembly:
https://winscp.net/eng/docs/library
If you want to stick with scripting, read:
https://winscp.net/eng/docs/guide_interpreting_xml_log
https://winscp.net/eng/docs/library
If you want to stick with scripting, read:
https://winscp.net/eng/docs/guide_interpreting_xml_log