Automatic enthalpy calculations for simulation of a condensing steam turbine

Hello! I'm currently writing my masters thesis and in my work I'm going to simulate the power output och three steam turbines (two back-pressure steam turbines and one condensing steam turbine). To calculate the power output I will use the mass flow and the difference in enthalpy between the inlet and the outlet of the turbines. Now to my problem: I want to use steam tables (superheated steam) to determine the different enthalpies but I don't know how to make a "double interpolation" in MATLAB as I first have to interpolate between pressures and after that I need to interpolate between temperatures in that interpolated pressure table. I've tried to look into programs like XSteam but it's way to complicated for my purposes. Does anyone have a quick and easy way to do this? The calculated enthalpies will be used directly in a Simulink model.

Best regards, Linus