I know this is a late response but, you can hook to the event MessageReceived
MessageType.SystemMessages = 57,
MessageType.SystemErrorMessages = 58,
(MessageType)2115 is something I use for fishing...I think the mapping of types is not up to date, so you might need to do some extra work to figure out the message type you are looking for.
Code:
GamelogManager.MessageRecieved += (sender, e) =>
{
if(e.ChatLogEntry.MessageType == SomeMessageType or number)
{
// do things here
}
}