Is there a way in DirOptus to lock folders and files so they cannot be deleted or moved, but would allow files to be saved to those folders.
You could edit a lot of things and put @ifpath ... clauses around them, but it would be a lot of work and probably wouldn't protect you from every possible way.
The only way to do it for sure is to use file permissions to block it from happening at the operating system level, but that may also prevent the other things you want to do in the same folder (depending on what they are, and assuming they would need to be done using the same user account, and without UAC etc.).
Personally, I have some areas permissioned to require UAC access to modify, which works well for this kind of thing. Although that is more to prevent media library programs from modifying my carefully tagged files, as they have a tendency to do.