Generate a random URL to a specific page

[eluser]Omaplie[/eluser]
Hi,

Thank you very much for you help.
One thing that I don't really understand.
How can I redirect the « hash URL » to the
good URL ?

I mean, how do you say (in the code) that
www.mywebsite.com/gfhjdkkjh will be redirect
to www.mewebsite.com/registration ?

Thank you a lot.