Posting Stock Award History on Ex-Employees

Summary

We would like to migrate stock awards on ex-employees, but aren't sure how to accomplish it.

Content

All:
 

Prior to being in HCM Cloud full-on, we were in EBS and used Information Elements to store previous stock awards.  That worked out fine, but in an ongoing effort to provide value to our employees, we would like to move all this data to the Stock Grants/Awards function in Fusion.  For active employees, we can do it fine via the loader, but for ex-employees, it doesn't work.  What is best practice for doing this?  Is it even possible?

Thank you,