How do you edit the properties of the rewind button?

Hello, Can someone please help me figure out how to edit the properties of the rewind button. I am creating a training video where I would like for people to be able to backtrack a little bit in case they missed a word or two, but I wouldn't like for them to move forward and just skip the whole video; this is why I do not want to use the progress bar. I enabled only the "Play," "Back," and "Mute" buttons in the playback control. I had enabled the "Rewind" button as well but it does the exact same thing as the "Back" button, so I really do not see the purpose on having both. Therefore, I was wondering if the properties to the "Rewind" button could be edited for it to do exactly what it entitles, rewind the video or at least just the sound. I don't want for it to begin playing the slide all over again or to go to the previous slide. Perhaps it can backtrack 5 seconds or so every time it is selected? By the way I am using Captivate 8. Any help is greatly appreciated! Thanks!