Attempt to add new spells and skills.

Maybe the heroes are different? I tried it with your file and with my modified NCF, but they don't even appear in the book.

Added 58 seconds later
I ran both your EXE and the NCF, but the result is the same.

Maybe something is wrong with the byte number?

Forget about NCF for now.

You need to run the H5_Game_vasik.exe file on a clean, patched version of the game 3.1 - the presence of the vasik_Kaspar_new_spell.pak file in the data folder is mandatory!

Damn! Just do what I wrote above, and use those files! Or upload your version of the .exe here.

In general, as I suspected, the .exe contains a list of all the spells:

 SSZ00E66F28_SPELL_EFFECT_FIRST_AID_TENT_PLAG:
 SSZ00E66F4C_SPELL_ABILITY_CUSTOM4:
 SSZ00E66F64_SPELL_ABILITY_CUSTOM3:

So, who knows if the script method will work for the new SPELL_ABILITY_CUSTOM5 spell.

P.S. I checked CREATURE_... and all the standard creature identifiers are hardcoded into the .exe, so who knows... maybe it's for the command line debugger, or maybe for something else!

P.P.S. All my attachments need to be unpacked, not just renamed from .zip to .pak! The .pak is inside the .zip!