Unable to Default enrollments to dependents when employee returns from LOA

Summary: Our requirement is when employee goes on Leave of Absence, all his/her enrollments should be end dated. And when employee is returning from LOA after some days, then all his previous enrollments (before LOA) along with options and dependents should come as default enrollments.

Example: Employee is enrolled into 'Employee + Spouse' option in Medical Plan and selected Spouse as dependent. Employee's enrollments are end dated when he goes on LOA. And when he returns from LOA, he should enroll into same 'Employee + Spouse' option in medical plan along with Dependents.

We are trying to achieve using Default formula at plan in Program level but only option is defaulted to 'Employee + Spouse' and Dependent is not selected in plan.