Changing the VATS type on a weapon

[robtest]

I am developing a new melee weapon with Cripple. By default, the VATS only lets me select the whole Enemy that I am fighting with. On guns in VATS, I have the ability to select which body part that I want to attack. I want to be able to cripple a specific body part, like take out the legs, in case I need to run away.

 

Any help would be appreciated...