Please refer this doc.
https://winscp.net/eng/docs/library_session_movefile
The code would something like
https://winscp.net/eng/docs/library_session_movefile
The code would something like
$session = New-Object WinSCP.Session
$session.Open($sessionOptions)
session.PutFiles(localPath/fileName, remotePath/fileName).Check();
session.MoveFile(remotePath/fileName, remotePath/processed_fileName);