How to use matlab class handle in simulink

Is it possible to use such an class in Simulink? I successfully worked with static methods, but it would be nice to use a handle class. The method should be fed with parameter b by a simulink connection. Using a Matlab function block in simulink I get an error "b not known".

      classdef Example < handle
          properties
              a
          end
          methods
              function ex = Example(a)
                  ex.a = a;
              end
              function out = compareWith(ex,b)
                  out = min(ex.a,b);
              end
          end
      end

[Stefano Cardarelli]

So... I am at your same point 8 years later... have you solved it? I'd really need some help right now!