Ho to pass managers personnelnumber to another column in Synchronization project

Hi All,

I have a requirement for which I am creating a mapping between person table and another database table to save person's manager personnelnumber into a Database table column.

For that I have created a virtual attribute with object reference type and am using Route = UID_PersonHead.PersonnelNumber. 

But when I created the mapping and trigger the sync, I don't see the managers personnelnumber being sent to the target database table column.

The logs does not show any error either.

But, when I simulate the sync project I get this error "Error Walking route UID_PersonHead.PersonnelNumber"

Could someone help me what can be done here. is there any other alternative like calling a script in the virtual attribute?

Currently I am on Version 8.1

Thanks in Advance!