Question on the news shock dynare example

Hi, everyone,
I am studying the dynare example :RBC_news_shock_model.mod.
It tells how to simulate an unrealized shock in deterministic circumstance, using the command:"y2 = simult_(temps,oo_.dr,shock_matrix,1);"
My quesion is , how to simulate an unrealized shock in stochastic circumstance, using “stoch_simul”.
It seems not possible to directly make stochastic IRF in the future, in the dynare circumstance.
So how should I work that out?

The simult_
is the function underlying stochastic simulations, not deterministic ones. You can also see this at
where this command follows the

OH ,THANKS A LOT, my dear professor!!!