French to English Other Certificates, Diplomas, Licenses, CVs Birth certificate

I'm translating a birth certificate from Belgian French to English and have both Echevin and Echevin délégué. I looked at the archives and found a great explanation for "echevin" (http://www.proz.com/kudoz/1592528), but in this text, it says the certificate was certified by "M. X, Echevin en remplacement du Bourgmestre et de l'Echevin délégué." So in this case, would it be that he is the alderman standing in for the Bourgmestre and the alderman who has been designated to stand in for (deputize) the mayor? And if so, would it be appropriate to speak of the "alderman standing in for the mayor and deputy mayor?"