[Proj] ETRS1989 to Greek Grid (GGRS1987)

[Leonidas Liakos]

Dear all,
recently I tried to convert some data from ETRS1989 (Lambert Azimuthal 
EqualArea) to Greek Grid. Comparing the results of the conversion, it 
seems that there is an important shift (error?) of those data.Is there 
any special tranformation method and parameters that I should use? Yours 
sincerely,

Leonidas Liakos
Geographer
32nd Ephorate of Antiquities
Hgoumenitsa,Greece