So...the Spectral Hand spell describes the spell as an incorporeal construction made from your life force. You use it to deliver touch spells at a distance. It grants a +2 bonus on your melee touch attacks.
Since the Spectral Hand is itself incorporeal, do you make attacks with this as incorporeal touch attack? I suspect in most cases the distinction will not be meaningful. On the other hand, in those cases where it is meaningful (say for instance, a target is allowed to apply its shield bonus to touch AC) it would be nice to know.