Hi,
The ACL can only reference to IP not to name.
If the server's address change they change within a range correct?
So you can configure the ACL to point to the range instead than the single IP.
i.e.
If the server 1.1.1.1 switches IP between 1.1.1.1-1.1.1.14
You can have your ACL point to 1.1.1.0/28
Just a thought.
Federico.