as I know things like spell power and attack power in other games are calculated by weapon damage and your max magicka/stamina values in ESO
in esohead skill calculator
for example a magicka consuming skill:
Assassin's Blade
has spell power and max magicka modifiers
and a stamina consuming skill:
Critical charge
has weapon damage and max stamina modifiers
its either your weapon damage=spell power (without any modifiers)
or it might be staff weapon damage=spell power and physical weapon damage=weapon damage
I never used a staff in game so I don't really know.
Please correct me if I am mistaken(if you are sure).