How to peg interest rate for some periods?

Hello professors. I try to simulate different monetary framework ,such as inflation targeting,price level targeting. And I need to peg interest rate for same periods to compare different effects of these targeting regimes. Fixe policy rate unchanged means that I should introduce some endogenous state variables into code to keep interest rate unchanged, is this trick right?

Thanks for your reply.

You mean in a perfect foresight context?

yes professor

Ok, and the question is about how to temporarily peg the interest rate or how to introduce monetary policy shocks to have the ZLB bind exactly?

Thanks for your reply, professor. I want to achieve like this. A shock that drives interest rate for hit the bound and stays for same periods.

But what is the shock here inducing the ZLB to bind?

In this paper is natural real rate shock.
ecb-wp2394-2.pdf (1.1 MB)

That paper cannot be reproduced with Dynare as they use global solution techniques.