You can add a static hostname as follows in global config mode:
host sbc.example.com <IP address>
host sbc.example.com 192.168.1.254
One caution: In many redundancy scenarios, a special DNS entry called an "SRV record" is used to resolve names used for specific services such as SIP. This entry is more than a hostname to IP mapping. It provides for failover and load balancing. If in your case "sbc.example.com" resolves to a single IP then this won't be an issue.
The ideal situation would be to fix whatever is broken with DNS.