Topic: how to create dynamic routes and helpers in rails3

i have a task to create mapping of different urls at run time .
In the application i have a GUI interface which displays list of routes from routes.rb file.
User has the ability to change that url to some different name from the interface
eg. (abc/mno) --user can change them to --(hello)
so if user type /hello in the browser request is redirected to /abc/mno
i have to store those mapped routes in a database.
how to add a dynamic mapped route to already defined routes(routes.rb) while creating a new record in database
how to add routes from the database while loading routes.rb file.
i am not able to figure out how to extend the default router so that it can include routes from the database ..
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i already know that by creating a controller that handles the all routing is possible...but that approach needs to restart the whole server in order to reflect the changed routes again
--even different url_helpers  for that method are not available....