I've never used that kind of syntax with curl before. While technically it should work according to the man page, I would probably try something like this:
curl https://webserver/filename.csv -o /tmp/filename.csv
I'm not clear if you need to add any flags after curl, like a header or something else. You'll need to experiment with that. Also, I see that it's an https server. Do you need to provide authentication for it to work? Like -u username:password perhaps?
