Just FYI, since I have not done any NPC quests, I do have a reference quide that was made by MWMDRAGON here. 
 
http://66.159.225.58/eqemu/EQEmuQuestLexicon.pdf
GeorgeS
 
quest::castspell 
Explaination: 
Makes the mob or NPC cast a certain spell on the creature with the indicated ID. 
Full Command: 
quest::castspell(id,spellid) 
ID = The ID of the creature the spell is to be cast on. 
SpellID = The ID of the spell to cast taken from the spells_us.txt 
Example: 
# Casts the bind affinity spell on the hailing person. 
sub EVENT_SAY 
{ 
if($text=~/hail/i) 
{ 
quest::castspell($userid,2049); 
} 
}