Hi,
I am also working on benefits currently .
I have almost similar requirement for creating of pension plans in IT0169.
We have written a routine if employee have a change employee or etc then the start date of the IT0169 should be next payroll run start. In the routine we have read table V_T549Q and our Period parameter 04 to get the next payroll start date and pass that value RP50D-DATE1 which i have used in the dynamic action
Regards,
Raja Sekhar