Then you want to save the index of the list item instead of directly setting the text to the sprite.
floor(random(List.ItemCount)) gives you the index. So add a instance variable to your Sprite - ListIndex
So first set Sprite.ListIndex to floor(random(List.ItemCount))
Then Set Sprite.Name to List.ItemTextAt(Sprite.ListIndex)
When you click sprite, use the list action Set Selection to Sprite.ListIndex.