How do I create a custom cantrip for prepared spellcasters?

[Hydrothermal]

I created a spell by copying an existing cantrip (acid splash) but it doesn't appear in the list of available spells when I add a level of Wizard and edit the spellbook. I can see it in the Sorcerer list if I add a level of Sorcerer, but it still doesn't show up in the spellbook list. It does work if I change the spell's level to 1. Any thoughts?

Relatedly, is it possible to add to the list of free spells that a Wizard (or other spellbook user) starts with, without copying and overriding the class?

 

[Mathias]

Here's a thread discussing this issue: http://forums.wolflair.com/showthread.php?t=56022&highlight=cantrip

 

[Hydrothermal]

Thanks Mathias. Checking the "Don't Include Free" box allows me to add it like the other rare cantrips, but I wasn't able to get the other method to work. I created a mechanic and gave it a bootstrap for the custom cantrip as ShadowChemosh suggested, but that just added the spell directly to all new characters. Is there a tag I need to set to make it appear in the spellbook instead?