You're using a Wacom with the Surface? Are you saying there's no way to use a Surface like a Wacom?
Many of the Wacom features are wired in to PS.
You would have to figure out a way for the Surface to emulate the Wacom api which for the surface; are not available.
People are clamouring for the Microsoft tablet mode to emulate the Wacom tablet features, but knowing Wacom they are not about to give Microsft their api interface.
They might not take nicely to the Surface eating the Cinitiq 13HD lunch at their own expense.
Suggest you move on in your endeavours.
Anything that may come down the line invariably will be some kind of unsupported hack.
Time to whip out the old check book and purchase a Wacom tablet.