Hi,
I'm more interested in the requirement than I am in the solution.
Can you explain why are you capturing DOB on IT0041 when it already exists on IT0002 and it is meant to be captured solely on IT0002? Points to consider:
1. Security/audit - From your screenshot (personnel area Alabama), it appears you are working for a US based client. If that is true, DOB is classified as personally identifiable information (PII) as per the guidelines defined by the National Institute of Standards and Technology (NIST). For that very reason, access to IT0002 is usually restricted. Access to IT0041 is much more open because it houses other dates that track important events such as hire, rehire, transfer, termination etc during an employee life cycle. To my knowledge, there is no standard way to restrict access based on fields within an infotype. It is all or nothing. With what you are trying to accomplish, you will not be making any friends with the folks from audit.
Refer: http://csrc.nist.gov/publications/nistpubs/800-122/sp800-122.pdf
2. Duplicate data entry in the database.
Hope this helps in evaluating the requirement.
Donnie