Set up your Help caption on one of the early slides and name it as cptn_HELP or similar. Set its Visible in Output to OFF. Set the caption timing to Rest of Project.
Create a user variable called v_HelpCaptionVisible or similar and set its value to 0.
Your Help button will need to execute a Conditional Advanced Action that checks the value of the v_HelpCaptionVisible and if it is 0, assign the v_HelpCaptionVisible to 1 and Show the cptn_HELP object, ELSE assign the v_HelpCaptionVisible variable to 0 and Hide the cptn_HELP object.
Thanks, Rod! I don't have the course with me right now, but I'll give this a shot tonight.
When the caption becomes visible, will it automatically pause the slide? Or will I need to add a Pause action as well?
You will need to add something to pause the slide. Either in the Advanced Action or else on the slide timeline (e.g. clickbox).
Thanks! I'll let you know if I manage to mess this up tonight.