Setting Armor

I know this may be a very noobish question, but I wanted to create some armor from the stalker games.

It’s not very complex, you just press E and your armor level goes to a specific number, though nothing like your appearance is changed. I don’t want to add armor, but make it a certain level. Say My armor is 50, and then I pick up a trench coat, it goes down to 20. But if I pick up an exo-suit, my armor goes to 120. Then when I pick up a trench coat again, it goes down to 20.

I think I’m half way there, I believe I use an activator called setarmor or something. I just need someone to tell me the function activator to use.

SetArmor( value )