Exclude Category Option

Hi, thanks for this plugin, it’s been very useful. I have feature request, is it possible to exclude a category using the shortcode? I have some posts with multiple categories but I only want to show posts from Category A and not from Category B. Even if the post contains both Category A and B. I hope that makes sense… I was hoping to do something like this… [recentposts-sc category=”categoryA,-categoryB”] Is that something that can be added to your plugin? Thanks again!