The PayrollProcessEmployeeBenefitSP property identifies the stored procedure that is used for calculating employee benefits that are strictly employer contributions and have no related employee deduction. For benefits that have an employee deduction and an employer contribution, such as a matching 401K plan, the procedure for calculating this is set up in the Benefit Plan section of Admin Tools.
Admin Tools location:
Config Option > Supplier > EmployerSetting
Any other custom stored procedure that properly handles employer contribution only benefits.