*sigh*
I'm afraid you can't just say:
Here's an Item Script ZC, I said something about NPC rock weapons, therefore you should shoot one for me!

What you've said is:
Code:
item script rock{ //start script
	void run(int Weapon){ //start void run
		NPC->Weapon(18);
		Game->PlaySound(51);
	} //end void run
}// end script
And how ZQuest reads that is:
Code:
This script is an item script, so put it in the 'item' compile menu.
	Run command for the script (loading an integer called weapon)
		Find the enemy that you've previously loaded called 'NPC', and set it's weapon to (18)
		Play the Sound effect number 51
	End the run command
End the script.