Movie where earth is an alien outpost where a weapon hidden in a volcano

Question

Movie where Earth was an alien outpost a very long time ago. A weapon is hidden in a volcano (and possibly forgotten); the alien race returns to switch off this weapon but is attacked by said weapon when entering earth orbit. A young girl teams with the alien that was in the space ship to stop the weapon and the creature controlling it before it fires again and the volcano erupts wiping out all life on the island.

I saw this movie when I was a kid in the 90s alone with "The distant home" movie so I can guess it was written and produced in Australia.

Answer 1

I asked on a different site with more comments and the answer that was correct was "The Boy from Andromeda" which was in fact a Tv Series.