I've seen this question, but it doesn't address my current issue (it's about getting the external IP address of the current machine):
Windows command that returns external IP
I'm on a network that has a number of external IP addresses. I need to determine the external address of an internal machine that may use a different external address. Obviously, I could go to a machine outside the network and ping it from there, but how do I do this from inside the network?
I would like this to be incorporated into an automated process, so a DOS command or PowerShell script would be preferred.