Is there a way to understand form which turn come a .2h file ?

[Gateway103]

I believe that Torvak's savegame utility can read in the turn number. Perhaps you can contact Torvak and see if he can extract the particular codes he used, compile it after some modification, into a turn # reader (e.g. scan all savegame files in the directory, display the turns associated with each one). Failing that, I think you can still use the savegame utility, albeit perhaps a bit more cumbersome for your purpose.

The utility can be found here On Arryn's, requires Java to run,
http://www.bl23c.com/arryn/downloads/domsaver0.61.jar

-Gateway103