Have a look at DECS and Lotus Script / Java, you can find a solution over there.
Also you can look at LECS for DB2 connectors, it is downloadable from the Lotus forum, then you can use the classes to access DB2 and get to your data,
If you are good with Script then I expect half day to test concept and 2 days to get a good working solution.
I used LECS with 4.6 and it worked perfectly.
One more thing use th ODBC connector from Java(JDBC) or the one provided with IBM for DB2 avoid the MS ODBC as far as possible it is too slow.