
First of all, install Debug Console Enabler, then hit the Tilde(~) key to bring up the developer console, and enter the code.
additem(name,#)
where 'name' is the Item code and # is item quantities (optional)
For example, to spawn a Negotiator type:
additem('Bear Pants 3')
Weapons
==========
Abarad
Addandeith
Aerondight
Anathema
Angivare
Anth
Arainne
Arbitrator
Arbitrator_crafted
Ardaenye
Ashrune
Azurewrath
Bandit Shield 01
Bandit Shield 02
Bandit...