Copy files between two remote servers with SFTP

You seem to be using SFTP mode rather than SCP mode

Try mput *.pgp (a guess based on FTP commands)

The manual says wildcards should work

put <file> [ [ <file2> ... ] <directory>/[ <newname> ] ]
If only one parameter is specified uploads the file to remote working directory. If more parameters are specified, all except the last one specify set of files to upload. The last parameter specifies target remote directory and optionally operation mask to store file(s) under different name. Destination directory must end with slash. Filename can be replaced with Windows wildcard1) to select multiple files. To upload more files to current working directory use ./ as the last parameter.

…

put *.html *.png /home/martin/backup/*.bak

You MUST put the target directory as the last item in the quoted command.

d:\winscp\winscp /command "option echo off" "option batch on" "option confirm off" "open sftp" "put D:\*.pgp ""C:\Documents and Settings\newtowinscp\Documents\Backups""" "close" "exit"

What about making your WinSCP script easier to maintain?

I suppose all you need is to put one synchronize command per directory to your script. That does not sound too difficult to maintain.

I.e. your script (script.txt) would be like:

open sftp://user:password@example.com -hostkey="server_hostkey"

# one synchronize command per directory
synchronize remote C:\local_directory1 /home/user/remote_directory1
synchronize remote C:\local_directory2 /home/user/remote_directory2
...
synchronize remote C:\local_directoryN /home/user/remote_directoryN

exit

And you add a task to Windows Scheduler with command-line like:

"C:\Program Files\WinSCP\WinSCP.exe" "/script=path_to_script\script.txt" "/log=path_to_script\script.log"

Ideally also add the /ini=nul to command-line to isolate your script from environment.