Example:
Adding a single file item

Actions used:

List Box Object - Add Files

In this example, we'll add a single file item ("C:\My Files\Important Instructions.txt") to the end of a List Box Object named "List of Text Files", and have it show up as just the filename with no file extension (i.e. "Important Instructions").

The full path and filename ("C:\My Files\Important Instructions.txt") will be stored as the data for the item.

Note: You could accomplish the same thing by using a "List Box Object - Add" action to add "Important Instructions::C:\My Files\Important Instructions.txt" to the list.