Breath weapons (fire, cold, bile) have strength /2.
Boulders have strength /3
The dom3 database uses -1 as strength, -2 as str/2 and -3 as str/3, too.
I tried it manually, the range field seams to be 31 bits + 1 bit for the signum (like most in dominions.
If you choose any number smaler 2^31 ( =2147483648 ) for the range, it get's cut down to range 100.
Sadly 2147283648 to 4294967295 (the 32nd digit being a 1 in binary) result in the weapon apearing as a melee weapon.
Can't trick the limits of modding.