What you seek is a generic Hebrew accent used in modern text books. It is not a Massoretic accent. So it is not one of the basic accents on the BW Hebrew keyboard. However, two forms of this accent are available in the bwhebb font, and can be accessed from the Windows Character Map, so that you can copy and paste them into a document using the bwhebb font. They are U+00F1 and U+00F2. I copied them and am pasting them here now:
They display correctly in the BW editor and other documents on your computer, but the program for this thread does not accept the BibleWorks fonts.