How to load the Prenotification Date and Prenotification Status Coming from the Legacy System

We have one requirement where to bring the prenotification status and date from the legacy system to cloud for all ready validated and prenoted bank accounts. This would happen through initial bulk load data migration activity only. After that system should take care of prenotification process for any new bank account related changes. But for the completed one, business don't want to do the prenotification again. However, the required HDL template or field attribute name was not found to use in the conversion process.

Hence, if any one can help me to know what is process to bring the prenotification status and date values for the prevalidated bank accounts, it would be helpful.