Search in a certain category – Widget

Hello! I have searched and installed most of the plugins hoping that I will found a plugin that could allow me to add a simple widget in my slidebar with 2 options to configure.

1. Title of the widget
2. Field to enter the category id to display posts.

The final work should be a search fild with search button in witch users can search just in a certain category 🙁

The problem is, that I was not able to find anything to work for me.
Could you please help me?

Thank you!