Custom Class - Count as Class

[Spaduba]

I am attempting to create a new class that uses the ki power ability from the monk. I can generate custom ability just fine, but it requires monk levels to be able to select the powers, which I don't have because it is a custom class. The option for "Counts As" Classes doesn't work as it's only for multiclassing.

Does anyone know how to make my custom class count as a monk for the purposes of using ki powers?