I think your requirement (2) "select files or folders" , after logging on, will present the greatest obstacle. If you know which files/folders beforehand, it would be alot simpler. See Copying files to an authenticated Win32 share

But if you want to navigate the remote filesystem, select items, then download them, it will require that you "maintain state" during the connection. That pretty much means you will need to setup a socket connection on your own, possibly with a gui, which will let you select from a directory tree, then download them. Maybe you could use ftp?

I don't think you will find a "quick-1-shot-script" to do this, at least not for free here.