I was thinking that perhaps you can convert in two steps: first with cpconvert(), from Greek Windows to Standard Windows, and then with strconv() to Unicode. But this is probably just a wild guess.
>Unfortunetely no,
>there is not any option to convrt from 1253 codepage to utf-8
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)