Change eligibility date for an employee moved to new EE subgroup

Hi Experts,

The requirement was to change the eligibillity date of an employee after 30 days from the start date of infotype 0171 only after once the employee has been moved to a new EE subgroup. I am able to fix this reuirement by adding the code in a custom user-exit. But i am stucked at testing point. When I am checking that employee using tcode HRBEN0001, it is still showing the same old validity period. Please suggest how i can test it. Its urgent.

Thanks in advance.