Maintain delivery condition in PO after PO output

Hello experts,

Have searched a lot for below requirement but could not find the suitable reply.

Scenario: X dept user will create PO and take output. Later, Y dept user will maintain different delivery conditions in each PO line item before first GR.

Control Required: (1) Y Dept user should have authorisation of maintaining delivery conditions only and not for the other changes / additions in PO line

                           (2) PO should not require any amendment for delivery condition maintenance.

Is there any tcode / authorisation through which Y dept user should be able to maintain only delivery conditions.

thanks