The Telstra T-Box in Australia is a completely different unit. As such, the Netgem codes won't work. If you have a learning mode for that app you could learn them from the remote, or perhaps try loading the Logitech ones listed as 'TelstraClear T-Box'.
I work in a contractor role for Vodafone in the Media Services Group.
Please note that I am not a part of the social media team and help out on my own time where possible.