Autonumber in Access Table

I have an access 2002 table that was auto numbered. Then I had records from previously that I have to input in this table. I need them to keep the numbers they already have. So I have 1451 records that already have numbers and then I need it to start autonumbering after those numbers. Is there any way I can keep the numbers that I have and then have it autonumber from then on? Oh please say yes and how.