Modding isn't done by poking around in game files (binary or txt ones), but by adding seperate mod files from which the exe reads what to change.
All those commands are listed in the modding.pdf, which comes with the full Version and is updated with every patch.
You know, there's some truth to the saying:
RTFM !
e.g. on the very first page you'll find:
1 Requirements
With the help of a simple text editor it is possible to create new weapons and units. It will also be possible to modify existing units and nations.
...
2 Mod Mechanics
All modding commands must be save in a text file with the .dm (dominions mod) extension.
...
• Mod Info
• Weapons
• Armors
• Units
• Spells
• Nations
• General
.. so if you check which commands are listed with each chapter, you'll know what's possible. If there's a command, you can do it (unless it doesn't work as expected o.c.
), if not, you can't, simple as that.