AddCommand is a weird Callback. When you have to set the ExtraData, you have to fill all other parameters with 0 and have to count how many 0's (I think there were 8 of them) and the datatypes are not clear (A Script Call needs casted types)
An other manko is that you cannot define your own AI-Commands (AttackBow, Guard) (you have to write helper callbacks)
My Suggestion is that the Parameters are stored into an array and you can define your own Commands:

AddCommand (object Clonk, string Command, array Params, int Timeout)

with the new Callbacks
function CommandAttackBow(object Clonk, array Params, bool& Done)
This function is called every 10 Frames till Done is true or 'Timeout' frames are over.