DTS How to...

I am new to DTS and I need some help. I have created a package which connects to an Oracle db, runs a query and then either inserts or updates a sql server table based on a DTSLookup. The package contains 3 connections and one DataDrivenQueryTask. It eventually will be scheduled to execute every 10 minutes.

Its working at the moment but there is one part I am missing. The table in Oracle has a field which contains the date the record was last modified. I have currently hardcoded into the where clause this statement LastModDate > trunc(sysdate).

This returns all records modified for the current day but of course, everytime it executes it will return records I have already processed.

Sorry, for babbling on but finally here's the question

How can I use a variable in my Source query? I was hoping I could store the last execution date/time in a sql table, retrieve it and use it in in the Where clause. Something like LastModDate > @LastExecuteDate. I am not sure how to set this up. Any ideas or pointers you have would be great?