Can additional funds required for personnel costs be reposted directly from the internal order for non-personnel costs of the project?
No, this is expressly prohibited. There needs to be a strict separation between “personnel” and “non-personnel” costs.
In this case, the funds for non-personnel costs that are no longer required are to be transferred back to the FWF (ideally, with the subject line “for personnel costs”). Then the human resources department or the payroll accounting office can request the required funding for the personnel costs from the FWF in the usual manner.