I don't think that maabadi realized that you posted this in the Microsoft Access Questions forum and gave you an Excel answer.
Access works very differently than Excel. The records really have no order within a table. Someone once gave a good description, saying think of records in a table like a bag of marbles, all jumbled up. So there really is no relative position of one record, as compared to another. If you were to sort them in a query, you could them loop through them in whatever sort order you determined.
To do what you want, you would use VBA that says every time a new record is added, find the maximum value in that field, and add one to it.
If you control all new record entry through a Form, you can just add the VBA code when a new record is submitted.
If you import the records, you can run some VBA scripts after import.
Note that users should NEVER enter records directly into the Table. You want to control all their data entry via Forms.