However un-ideal this situation may be, your best option is probably to setup a CNAME entry in your DNS pointing to the A record of the laptop (i.e. Server). This way clients cache the CNAME record rather than the A record and DNS server will be responsible for handling the IP resolution. Have the users connect using the CNAME entry.
CNAME of resource.domain
A Record of laptop.domain
When the laptop changes it's IP between connections it will update the A/ PTR record which will then be reflected in the CNAME record.
EDIT
I thought about this again and my answer still does not solve the issue. Even with the CNAME record clients will still cache the response they receive back from the DNS server. You would need to stop the clients from caching responses or lower the cache time. You could do so with editing the DWORD value MaxCacheTtl
&MaxNegativeCacheTtl
found at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters
. change these values to how many seconds you want to cache entries. Reference: Disable Client-side DNS caching
Be aware of the impact this will have on your network/ clients.