How to make Employee Expense Account and email id mandatory in Employee form ?

Hello.

We wish to make below fields mandatory in employee form.

a) Expense Account

Application/Responsibility: Human Resources

Navigation: People > Enter and Maintain. Query the employee name. Click on Assignment. Click on Purchase Order Information.

b) Email id

Application/Responsibility: Human Resources

Navigation: People > Enter and Maintain. Query the employee name  > click on office details tab

Did anyone do this before using form personalisations or any other means.

If yes, please let me know the steps.

Regards,

Katherine