I would need a decent closeup of a leafybstem to even make a suggestion. Blowing up a photo suggests that the leaves are short and broad and arranged in a decussate fashion (pairs at right angles to each other) which narrows what it could be for anyone who is familiar with subalpine species. You really need a photo of flowers. I sent the sighting on to Jackie Miles, who is expert on Kosciuszko flora, and she does not know what it is either.