You can only connect an MS Planner project in Microsoft Project is your project is an enterprise project stored in Project Online. There is no way to connect a desktop only project (saved as an MPP file) to a Planner project. Hope this helps.
If you apply the Board view in Planner, you can click the Filter button in the upper right corner of the page. There are a number of built-in filtering options on the menu. If none of those work for you, however, you would need to filter the data in Excel. Just a thought. Hope this helps.