There's no lock. But you can do it like this:
- first move files that are there to different temporary remote directory, specific to retrieving machine (e.g. /tmp/retrieve1 and /tmp/retrieve2)
- download files from the temporary directory
Btw, mv command is for the first part (moving between two remote directories), to move files to local directory, use "get -delete".

I want to use the MV command to GET files from a unix host to the local windows server, winscp is running on the windows server. There will be two servers running the retrieval process in parallel for redundancy, but I don't want both servers to try and move the same file.

I can't find anywhere in the documentation that describes whether winscp will put a lock on the source file on the unix server and if other winscp sessions will honor that lock if they see it.

Thanks