setglobal will do it (assuming qglobal is set for the npc to get the global)
setglobal(varname,value,options,duration)
use option 5 for all zones, 1 for just this zone. This table might help with the option values:
Code:
------------------------------------------------------------------
value npcid player zone
------------------------------------------------------------------
0 this this this
1 all this this
2 this all this
3 all all this
4 this this all
5 all this all
6 this all all
7 all all all