Reduction of 401(K) base amount /102

Hello Experts,

There is a requirement for some employees to reduce the /102 (base for 401K) by the total of all the pre-tax deductions.

To cater to this i had written a PCR (ZXXX) and placed it in the benefits second call, but this is causing issues.

Upon encountering a retro the PCR UD31 replaces the unreduced base amount with the base in the previous run (reduced). This is then encountering the PCR ZXXX and the base is getting reduced again.

I was hoping if any one could point out any BADI that can be used to cater to this requirement.

Thanks,

Mike