I see that users have been suggesting that this would be useful for many years now! I would also really like to do this. When we have an active problem with remote devices that use dyndns we often find that the IP changes frequently as the device reconnects and gets a new assignment. The PingPlotter logs are useless after a reassignment of a new IP because it only queries for DNS resolution once. I understand that there may be issues when there are round-robin DNS names but we need a way to force regular DNS resolution of a monitored FQDN. This could be based on the returned TTL or forced to some other interval by the user. Here is the most recent thread on this from another user with some useful suggestions.

http://www.nessoft.com/forums/ubbthreads.php/topics/2067/Monitoring_route_to_a_target_g#Post2067