Making a transformation use a wig (Equip Slots)

[Myst42]

I'm making a personal tweak of this alternate Vampire Lord transformation mod by Shaydows, which if it turns good, I might even share, provided nobody opposes and someone cares

Actually, most of the tweaks are already working.

But I want one more thing, and I have no idea how to get it done

 

I want to make that mod use either a wig, or an alternate hair when changing from human to VL. The idea is to change it to a multi colored hair.

Currently, the VL change on the base mod keeps the human form with your char's hair, and equips an armor made of several parts.

 

One of those parts is a "helmet" which are actually horns

I want to change that into a wig, or a different hair

HOWEVER

 

No matter what indicated slots I select, the things get equipped but the human form hair is still there

It should work like a helmet, things gets equipped, the other hair goes away, but its not happening

Why?

I was told by tutorials, the hair slots are 31 and 41. I tried this tutorial to make the hair I wanted, into a wig, simple enough, combining 2 nifs. Also tried keeping the hair as a hair (hair and hairline nifs), creating a hair ID and using it as a head part, which worked a little better, except when I tested having a different base hair as a human, after the transformation, the VL hair was added, but it didn't replace the base hair either

Any idea what a I doing wrong? Is it even possible?

 

PS: I realize keeping the human hair unchanged is probably more desirable, but I'm aiming for something specific here and it would be just an alternative, so that when you change, your hair does too.