Gali 2008 chapter 3 Exogenous Money Supply

hello,
I got stuck with the dynare codes in Gali 2008, chapter 3 section 3.4.2 (page 56) "Equilibrium under an Exogenous Money Supply". Please can you direct me how to incorporate the Money Growth Rule in the Interest rate rule codes.
Thanks
I got stuck with the dynare codes in Gali 2008, chapter 3 section 3.4.2 (page 56) "Equilibrium under an Exogenous Money Supply". Please can you direct me how to incorporate the Money Growth Rule in the Interest rate rule codes.
Thanks