You are using the wrong timer command.
*addtimer(<ticks>, "NPC::OnLabel")
*deltimer("NPC::OnLabel")
*addtimercount("NPC::OnLabel", <ticks>
These commands will create, destroy, and delay a countdown timer -
addtimer() to create, deltimer() to destroy and addtimercount() to delay
it by the specified number of ticks. For all three cases, the event label
given is the identifier of that timer. The timer runs on the character
object that is attached to the script, and can have multiple instances.
When the label is run, it is run as if the player that the timer runs on
has clicked the NPC.