You are running the file locally or on the remote system? I don't know anything about Putty and, in your example syntax there is no reference to a remote machine.

That's the kind of error you get when:
1. You're putting in the wrong host name
2. You're putting in the correct host name but you're having DNS issues (temporarily using the host's IP address is a good way to test this)
3. You're putting in the correct host name, it's DNS name is being resolved correctly, but a port is not open
4. The SQL Agent account you're using does not have access to a system (sometimes people set the error that way for security: this vs letting hackers know they've found a live system but don't have access).

Also note that, local admin rights doesn't give an account access to a remote system that it doesn't otherwise have access to.