Force palette on chars from the select.def

[Orochikyocr]

Is your feature request related to a problem? Please describe.
I have a Ryu from SF character that has ex-modes like Evil Ryu and Kage, every one of them with their own sprites and move set.
These can be accessed according to the palette chosen in the select screen.
But I would like to separate these two from the main Ryu and use the slot system to have the 3 inside one single slot.
I have to tweak a lot of code inside the char, duplicate files, etc.

Describe the solution you'd like
slot = {
ryu, pal=[1,6], next=w, select=/s+a; this Ryu can only use pal 1 to 6 so when chosen it will be normal Ryu
ryu, pal=[7,11], next=w, select=/s+b; this Ryu can only use pal 7 to 11 so when chosen it will be Evil Ryu
ryu, pal=12, next=w, select=/s+c; this Ryu can only use pal 12 so when chosen it will be Kage
}

Additional context
Add any other context or screenshots about the feature request here.
Mugen creators used palno trigger to add ex mode to their chars, with this feature we can easily separate ex modes from their "main" counterparts.
Of course, the user has to know what palno the creator used to activate the vars that control the ex-modes.

Thank you in advance.