No you can't yes you can. If you read the excellent long post above you will see that for DOMESTIC commercial operations, the limitation is entirely up to the ICAO Contracting State (i.e. country) to decide for itself. In OZ we can fly commercially within our borders to any age in command providing the co-pilot is under 60 and subject to a more stringent proficiency and medical checking regime for the old farts. The same rules could not be applied practically for, say Singapore or Hong Kong, because every flight from those small States would cross borders and so would be international.
Other relatively small (in area) countries may have adopted the ICAO stance on international flights as a domestic policy for practical reasons, i.e. insufficient domestic aviation to be worth the double standard. Other countries may be driven by pilot union policy where the union is powerful enough to influence regulatory politics (France, USA?).