Help:optimal moentary policy in BGG(1999)model

I am interested in the opitmal monetary policy with the bgg framework.
Should I take the Linear-Quadratic approximationsof the utility of the household for the plan objective ?but how?are there some paper and dynare code with details i missed?
can you help me ? thank you in advance!

Check the paper by Chistiano, Motto and Rastagno … mirage.htm

thank you very much.
but i also have some questions:
1.when i analyse the optimal monetary policy ,do i have to take the linear approxmation of the utility? but Chistiano seems not to do that.
2.the dynare code for the notes seems not to work(especially the ceebgg.mod).

so,i seems a stupid idiot,but i also hope for your answer.
thank you for your patient!