Create a package with the function
Armor::onTrigger(%this, %obj, %slot, %val) in it and call the parent, then check if
%slot is 3 and write your code there (e.g. calling that function).
%this; use it as a quick way to access attributes of your playertype
%obj; the object of the player using your playertype
%val; a boolean, representing if the crouch button was pressed or released
Although,
I recommend not using a package and changing the function from Armor::onTrigger to yourDataBlock::onTrigger.