Is this possible, I can wake and shutdown my pc when at home connected to my home network but would like to do the same when im away from home on a different network

Hope somebody can help

Well you will need to port forward the UDP 9 port to any of your IP address from your home router. After you've do so you will be able to wake up your computers from outside your home network.

Indeed. For those who have more than one computer to manage, you can change the UDP port number within the client and then you can port forward on router to more tnah one internal computer

Hi, many thanks for trying to help but I'm afraid I'm a relative newbie to computers, I do know the ip address of the computer which I need to wake though, is this the ip address in question?

Yes. You will need to set up a port forward from your router. Go to http://portforward.com/ to see instructions for your router.