DTS Select Using Record Position

Hi there, it has been a while since i have posted. I am in a
situation where I am stumped. I am learning to build a dts package
where I am connecting to a table in an AS400. This database is being
maintained by an outsourced company and therefore I can't change the
table structure or even ask them to. Anyway, this table currently has
about 104,000 records. I am building a package to check it and pull
out the most recent records and put them where they go in my SQL
Server 2000 tables. The only way I can think of to get the most
recent records is to use a global variable in the package to remember
the record count and then get those records from that record position
on. Problem is, I have no idea how I would go about selecting records
from a record position. Does anybody have any ideas or should I be
using a different approach? There are no time stamps to work from. I
was told that the AS400 records, including updates, are appended to
the table, which is why I thought this approach made sense. I would
truly appreciate any help.