Multi Threading in Sharepoint List..

Hi All,

     Could you please provide some pointers on Multi Threading in Sharepoint List. My requirement was i have a list of Product Id's, i want to access those list of product id's to query in a Huge List (List Having 3 lack records consider LIST A) matched records need to move to other List (consider LIST B) and remove matched records from LIST A.

     For this requirement, we already wrote one small console application but it takes somuch time to do the above process.

So i am decided to fast up process by developing using  "Multi Threading in Sharepoint List"

     Please provide your valuable Ideas...

     Thanks in advance...

Somasekhar.