If I was to take a stab at a guess, I would say change this spell's data ...
http://thehiddenforest.dyndns.org/spell.php?id=2821However, there are two spells "Harm Touch" along with a few others related: Dragon Harm Touch, NPC Harm Touch, etc. It could be the other one (which has a lower max damage of 701), but it is likely this one which caps closer to what Sarcon said at 981.
Hard to say, but there would likely want to change something in effect slot 1 which is:
1 : Effect type : Decrease Hitpoints by -1 (L) to -981 (L70)