No, you can have only one type or permalinks for all the posts.
However, the “ugly” permalinks always work – no matter what your new permalink settings are. (Of course, it is NOT true the other way around)
You have 2 options: you either learn what to do with the htaccess file – or you give up changing the permalinks. Using_Permalinks – reading the manual is always a wise thing to do… BEFORE you attempt any big change in your blog.
Longminh I don’t think that your issue is anything to do with the .htaccess file. I think it is to do with the way that “special” characters are filtered out before creating page names within wordpress. You would probably have to alter the core code to achieve your objective.