Custom spell problem:

In the warcraft editor after making a custom spell, and trying to associate triggers to it, I found that the spell does not add itself to the list, is there any way to fix this? Would JASS be able to add it as custom text?

Which list exactly?

Make sure you set Hero ability to True if you need to, unless I'm misunderstanding what your trying to do.

Maybe you are talking about the list in the conditions(triggers) ability being cast = X, which lets you choose the ability being cast?