You have a few options, depending on exactly what you are trying to do. 

You can run a report in SpiraTest, filter on the test case folder, and specify Excel format. But if you need the test steps, then Excel output doesn't work very well. Microsoft Word would be better.

Using the Excel Add-In, you can only pull in all test cases for the project. Of course, afterwards, you could delete the ones that you don't need.

If you want the tester to actually run the test cases, and then you would like to have their results uploaded into SpiraTest, there's a very handy feature of the Excel Add-In that allows this. The tester would need to have an account in SpiraTest, but they don't need to be logged in to it while they are running the tests. On a machine that has Excel, the Spira Excel Add-In, and internet access, they import their assigned test cases and test sets into Excel. See section 1.3.8 of the Integration Guide for details.

Regards,

Elise