Need to manually create Seniority rows

Summary:

Need to add new Seniority rows using HDL

Content (please ensure you mask any confidential information):

We have accidentally hired 2 employees into HCM under a brand-new person number. Technically, these workers have multiple person numbers. Unfortunately, this issue of duplicate person records has been identified later in the year & payrolls have been completed. We cannot cancel the work relationship & rehire under old person number.

Now, we are trying to fix this employee's Seniority information. We would like to show his old person number seniority history under his new person number. I am able to do the adjustments. However, I cannot get the data to show like history. Employee would like to get his original start date corrected.