Only mget new files with smbclient

I'm using smbclient to access a shared Windows file system. I cannot mount it, because I don't have the permissions. How do I mget only the files which are new or have been updated? (Likewise mput). I don't think I can use rsync, because rsync only works if one mounts the Windows FS, which I can't do. I can only access it via smbclient.