Using Variables to create a drag and drop with images and transfer image names to a list

I am trying to create a learner experience in which a learner can choose from 20 images to identify their top 5 strengths and challenges. This  data would then be saved in a chart for use later in the course.   I have 20 images w/text on a slide.  I have used motion paths with a trigger that once a pic is selected it is moved along a motion path to a "strengths" box. This seems to work however I would also like to create a chart from the 5 images that are selected and save this list for use later in the course.  I am now stuck and can not figure out a way to create a list of the 5 strengths selected. Can this be done?