Yes, Viktoria, there were Aussies in North Africa. I wonder if the medal had anything to do with the fighting in Cyrenaica, Italian Libya. Cyrenaica had been part of Egypt at sometime before Italy invaded around 1930.
I don't think it is an 'official' medal, possibly a masonic lodge commemorative for lodge veterans or if they were in North Africa something they picked up there.
OP are there any places connected to your relatives that have initials CEC? Towns, counties, parishes, do Au states have Counties/parishes?