Inserting new characters from the Insert Characters menu will add new characters to your font, correctly mapped. Now you have to either draw or import the glyph outlines to create the designs that you wish to use for those characters. The blue outlines are just the glyph outline for that character mapping in the template font.
Okay that is actually helpful. But now I need to know how to draw or import the glyph outlines. Any ideas of how to do that? I just need to do 2 characters…uppercases for an incomplete font set.
Otherwsie, draw a letter on paper and scan it into a paint program, and cut and paste the bitmap into FontCreator, or using a vector drawing application that can save the image as Adobe Illustrator or PDF format, and import the vector image.