I am trying to create a "dropdown" box on a spreadsheet (that is linked into
a powerpoint template) that allows the user to select items. However, I need
the user to be able to select multiple items from the list. The list the
user can choose from is fairly large so I only want their selections to
appear in the box, instead of showing the entire list.

I tried the data validation but saw no option to allow multipl values. I
then tried adding a list box, but then all the values show....

How can I do this?

Thanks