EBP - Confirmation approval screen

[Nicholas Brand]

Hi,
 
We're using EBP 3.5 with a 4.5b R/3 back-end.
 
In our system confirmations are being created by a program.
The creation of the confirmation triggers a workflow.
The shopping cart requester receives the workitem.
When the workitem is executed the requester sees the 'Approve Confirmation'
screen.
In this screen the quantity and net price are greyed-out.
 
Is there a way to allow the approver to change these values before
approving the changed confirmation?
 
I wondered if it's an authorisation/attribute setting.
 
Alternatively is there an alternative approval screen or would it be a case
of building our own?
 
Thanks!
 
 
Kind regards,
Nicholas Brand