Add fake "Back" and "Next" buttons to navigate between questions within a block

Hello, I would like to show one question at a time within a block. Participants can press fake "Back" and "Next" buttons to move back and forward between questions. In doing so, the questions within the block show up like one question per page. I also hope to hide the first question (Q0 in the QSF) and the last question (Timer in the QSF). I have attached the QSF file. Could you help me to write the JS code? Thank you for your time.
mc2020_-_Copy.qsf