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Make a simple volt reg to 36V   (  or 33 if you prefer  )  and run this via a resistor to the Cathode of the 431,   use dividers to the Ref  pin of the 431,  the other pin goes to gnd

now the 431 will survive and the cathode will pull down when the divider string forces more than 2.495V  on the Ref pin,  calc the worst case dissipation in the 431.

you're welcome