You can always go into DNS snap-in on the domain controller and make a CNAME or A host record for the filer manually. Here is what I would do:
1) Change the IP of the filer during a maintenance window.
2) Go into DNS snap-in on the domain controller Update the IP address for the DNS record manually. (If you just create a brand new record or an alias, some client may resolve to the old address, causing problems).
3) Go to a windows client, open CMD, and run a "IPCONFIG /FLUSHDNS" to ensure the dns cache on the client is clear.
4) Test access to the filer to make sure it works.
Juist my two cents.