You should be able to find code online to construct a valid and unique bookmark name. An example of such a macro can be found here
http://www.vbaexpress.com/forum/show...-VBA-Bookmarks
Note that Greg's code is not bulletproof but it is a good case study to get you over the next hurdle. Shortcomings of that code, which may or may not matter to you are:
- Doesn't verify whether the bookmark name already exists
- Doesn't truncate string to the maximum length allowed by bookmarks