Your time period for an appeal has passed. You only have 30 days from the date of the entry of the final decree to note your appeal. It does sound as though you were notified about the hearing because you make mention of even hiring an attorney to represent you that day. It does sound as though you could have made some objections to the manner of service back in 1992 but if you never did anything, I do not believe the court will even consider reopening this case.
Ultimately, I believe you have a deeper concern here. What is that you really desire? Is there some provision in the decree that harms your interest? I think you really need to sit down with an attorney and discover what the real issue is here.
Sign up to receive a 10-part series of useful information and legal advice about the divorce process.