It can't be made.
Oh, are you sure? I think it is possible..Let's create a simple one in mind shall we?
Ok we start with the zombie add-ons script, a zombie
can hold a weapon (OnBotTouch->Bot->SetItem->Sword), but they willl still fight with their hands, so we modify the script that way that it will shoot instead of it will only use his hands.
Then we will make some models and voila the start of the battledroids is born..
(sure the add-on will be more then that but this is a example of how it
could work)
(the weapon add-ons would be even easier,model of a weapon, standard script for guns (little bit modified ofcourse), projectile=laser)
This would be the easiest way to create this add-on i talked about, but correct me if the above is wrong...

Oh and is this what i am talking about what you want in this topic, transformer ?