While many of the following posts use OpusScript, you may be able to implement similar capability with Opus standard triggers and actions ('Basic').
viewtopic.php?t=1971&highlight=user+images
viewtopic.php?t=519&highlight=user+images
viewtopic.php?t=982&highlight=user+images
viewtopic.php?t=2727&highlight=user+images
viewtopic.php?t=2952&highlight=user+images
As for User adding own words, consider that as two steps: User typing in text input, and some way to Save the data off to storage whether .INI file, .txt file, Excel sheet, or database. (Array variables, especially if you can get into scripting, are very powerful ways to manage sets of data and also for doing the match-up to your image.)
Very generally, do some Searching here on forum:
try: input user
try: write file
try: database
Once you get beyond the concept and can better outline what you're wanting to achieve and where you're stuck, that will make it easier for me and others to respond with more specific help. One thing you'll find with OpuPro is that there are usually many ways to accomplish something, some direct and some very creative.
Good luck.