Wordpress Perma Link Problem

I am trying to add this -?- into a post url, and it keeps shortening it to just - does anyone know how to get round this?

I'm not sure about getting around that in the admin area of WordPress, but you should be able to edit the permalinks directly in the database.

But if you make the change in the database, watch to make sure it's not changed back if you edit anything on that post in the future.

You can use the core function add_rewrite_rule() but you need to know some wp coding/regexp stuff