Library Name in URL

[Howard HH HUME]

Our URL for our web pages seems too difficult to remember
for some of our users.

http://www.ndu.edu/ndu/library/library.html

We'd like to use something like:

http://library.ndu.edu/

Do we have to register this domain name or is there simplier
way to establish this name since our parent organization
already owns "www.ndu.edu"?  Unfortunately, the answer of
talking to our Information Management people only works when
you know the answer in advance.

Thanks very much and please answer off-list if this is too
simple or off topic to interest others.

Howard Hume
NDU Library