To represent it, you would need to choose a Greek name with a similar sound or meaning:
* Αλέξανδρος (Alexandros): This is the most straightforward option, as Alec is a diminutive of Alexander. This is the full name, not a direct equivalent of the shorter "Alec".
* Άλεξ (Alex): This is a common transliteration of "Alex" in Greek, which is already a shortened form of Alexander. This is probably the closest you'll get to a Greek spelling of "Alec".
Therefore, Άλεξ (Alex) is the best approximation. Using Αλέξανδρος is accurate in terms of origin, but is not a direct equivalent to the short form "Alec".