Changing Hit Die type without a template

[SacredRogue]

Trying to add the Dread Necromancer class from Heroes of Horror, but ran into a little trouble.

At 20th level, they get an ability that makes them undead, and converts all their hit die into d12. I originally tried to use a template linked to the class ability to reflect this, but no matter what I do, it adds the template at the first level of the class, rather then the twentieth. I want to add the hit dice change to the ability itself, but I don't know how to code it.

If anyone can help (or tell me how to make the template not add too soon), it would be much appreciated.

[Lawful_g]

Do you know how to use bootstrap conditions? Is that not working?

[SacredRogue]

Guess I don't know how to use them properly, somehow I managed to not even notice the button there. What would I need to put there?

[Lawful_g]

First 500
count:Classes.XXXXXX >= Whatever Level

Where XXXXX is the name of the Dread Necromancer class tag and Whatever Level is the level at which you want the template to be applied to the character.

Hope that fixes it for you.