Sir, this "Yonaka desha" mentioned by King Ashoka is not Macedonia, but Bactria. which is modern day northern parts of Pakistan and Afghanistan. During Alexander the great the Macedonian empire reached to the banks of river Sindhu. And when Alexander died, his genarals divided the empire and Bactria (Afaghanistan) became an independant greek state. And during King Ashokas time Bhuddhism spread to Bactria and it became an important bhuddist kingdom same like Sri Lanka.
Seleucus Nicator supposed to have handed over the territory under him to Chandraguptha together with his daughter (Helena) when he had a call of duty in Egypt. Not that chandragupta fought and conquered parts of Afganistan. BTW, where did Chandraguptha and his grandson Asoka spent their last days?. In South India (Karanataka). All these info are at your fingertips via Gemini on your mobile!.