Result calculation when reporting to an LMS

Hi,

I developed a game for a company in Storyline 360. It has 16 questions (10 pts. each) and some bonus questions that are optional (1 to 4 pts). For the passing score calculation, we want the denominator to be fixed to 160 points, no matter if they answer some bonus questions. Now, if they fail a bonus question, the score drops since the numerator remains the same but the denominator increases by the bonus question value.  

Can we modify the way the course will report the final score to the LMS? The required score to pass the course is 80%.