I guess it depend's on what you like to modify..
You can find the radius in the gamedata.ini:
;======================= SPELL DATA =========================
#define SPELL_HEAL_RADIUS_CURSOR 200.0 ; Cursor size for heal spell ; RotWK originally 150.0
#define SPELL_HEAL_RADIUS_UNIT_SCAN 200 ;100.0 ; How far to scan for units to heal ; RotWK orginally 150.0
#define SPELL_HEAL_RADIUS_HORDE_SCAN 225.0 ; A little bigger so that if some horde members are within the cursor, scan will find the horde brain ; RotWK originally 200
Sound, requirement and a link to the radius in the specialpower.ini:
SpecialPower SpellBookHeal
InitiateAtLocationSound = SpellHeal
Enum = SPECIAL_SPELL_BOOK_HEAL
Flags = WATER_OK RESPECT_RECHARGE_TIME_DISCOUNT
ReloadTime = SPELL_RECHARGE_TIME_TIER_1
RequiredSciences = SCIENCE_Heal
RadiusCursorRadius = SPELL_HEAL_RADIUS_CURSOR
End
Something also in the commandbutton.ini and the commandset.ini.. and i guess nothing in the attributemodify.ini. - That's the stuff from RotWk, not Edain, but I suppose the differences are only the other image and description.