Manuel,Many of Finale's menus only appear when you are in a certain tool. The Shape Designer menu only appears when you are in the Shape Designer. I am not sure how you get to the Shape Designer in Finale 97/98. Take a look in the index file (online documentation): Fin IX.pdf.
In Finale 2001 you can get to the Shape Designer from the Expression Tool and from the Text Tool.
Your question about contemporary notation is a bit vague. Whatever it is, it is probably possible in Finale. Usually there are at least two solutions to any Finale notation problem. I have been using Finale for 7 years, and I haven't yet found a problem that Finale couldn't solve (although I have been trying really hard!). Some problems, however, require a complicated solution that can be hard to figure out or takes a lot of work.
Could you be more specific about "contemporary notation"?
Peter