Excel - populating data (checkboxes) based on combo box selection

Hi Leith,
I noticed you helped out an individual on this forum (similar to what I am currently struggling with), so I thought you would be a lifesaver!

I'm creating an Excel 'form' where the combo box values are a list of countries (approximately 75). Based on selection, the cells to the right would populate all "responsibilities" associated with that country. As mentioned above, I found a similar example, however, what I'm having trouble with now is adding additional countries and adding additional lines/responsibilities with checkboxes. Each time I try to add a new line to the list, I'm getting an error. Please help! I've spent hours and I'm not getting anywhere...