Employee should only withdraw scheduled leaves

Summary

Employee should only withdraw scheduled leaves

Content

Background: Belgium payroll is payed in advance, therefore is paid based on scheduled leaves.

The business needs to detect when a scheduled leave was changed by the employee.

A proposal is to apply the withdraw mechanism to scheduled leaves. In the way the employee can only withdraw the scheduled leave and not change it. The employee would need to create a new leave for the change.

The question here is, how can I configure the system in order to have the Employee only to withdraw an scheduled leave and not change it?