how to use evalin?

hello, i have a cell s, and s{1} = 'EngDa_jEng_C',now i want implement the commands(EngDa_jEng_C = Simulink.Parameter),i want realized in a script, i want use evalin, i try use following, but failed,what is the right way?

evalin('base',' s{1} = Simulink.Parameter');

[Walter Roberson]

Please read http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval for information about why we strongly recommend against creating variable names dynamically.