The plaintiff in any civil action in which garnishee process is served upon any person in any way obligated or liable under any mortgage or lien upon real estate, garnisheeing a debt or any part thereof secured by such mortgage or lien, shall, on or before the return day of such process, cause to be filed, in the office of the town clerk in the town in which the real estate is situated, a certificate giving the names of the parties to the action, the time when and the court to which such process is returnable, the amount of damages claimed and a statement that the debt secured by such mortgage or lien has been garnisheed. The town clerk shall record such certificate and note the same on the page on which such mortgage or lien is recorded. If such plaintiff recovers judgment in such action for the debt sued upon or any part thereof, he may file for record, in the land records of the town where such mortgage or lien is recorded, a judgment lien upon such mortgage or lien within four months after the date of such judgment, and thereupon he shall be subrogated to the rights of his judgment debtor in such mortgage or lien to the amount due him upon such judgment, and the rights of such judgment creditor shall not be affected by any instrument not appearing of record prior to the time of filing the certificate hereinbefore described.