Regarding the Create Thumb button in the Admin screens

This feature is nice but I have some videos where the first second or two is black or solid color with a text like a title or credit. I find that no matter how many times I click on Create Thumb, the first thumbnail is always from this black section. Is there a way of selecting one of the other thumbs that were created so that would become the main thumbnail when the video is shown as a recently viewed video?

Thanks.