Modsecurity custom error page?

I currently use modsecurity under linux 2.4/apache 1.3.x. When a rule happens it simply ends up using the default action:

# Default Rule
SecFilterDefaultAction "deny,log,status:412"

Giving the generic Preconditioned Failed 412 page.

How can I change this to forward to a custom html page I made?

And does anyone know a good modsecurity support forum out there?
You would need to change this in WHM. Just go in there and there should be a mod_security page that you can edit. I can't remember exactly where it is but I know all of the error pages are able to be edited from within WHM.