Enable merging of two extensions to combine data for analytics

We have had at least two instances of either a bug or having to switch a user to a new extension because of an issue. The problem that happens is that the analytics data stays with the old extension number, which ruins the ability to analyze things over the entire duration of an employee's time with a company. I can only imagine how many extensions "could" be created over time for many different reasons. If you could "merge" the data for two extensions by one employee, that would enable you to have accurate, long-term metrics for an employee.