Can you explain what you are trying to do with this list? Is this for selecting the name you want to enter into a field? You can put a scroll bar on a field that is formatted as an edit box but not one formatted with checkboxes. But there are a number of ways to set up a portal with a scroll bar for listing values with buttons and those buttons can look and act like check boxes or radio buttons.
This is a topic covered in the free download: Adventures In FileMaking #2 - Enhanced Value Selection.
But note that I am making assumptions about how you will use this that may not be accurate.
Where in the file do I find: 'Enhanced Value Selection.'?
The list will be a 'toggle' to select/deselect names with a 0 or 1 value so that their associated values are zeroed or counted.
Enhanced Value Selection is the subject of the entire file. (Adventures in FileMaking #1 covers a a different topic--conditional value lists.)
Each large button in the button bar except Intro and Additional Resources takes you to an "exploration layout" for a different enhanced value selection technique. Click the button named "Check Boxes with Scroll Bars" to find the Exploration layout that I was recommending in my previous post.