Can we Override Qty field in Teleservice Charge lines and calculate Net price based on new Qty

Once CE add the detail for charge lines upon debrief, Agents are often being requested to update this on SR form Charges Tab, and currently the only way to do this is in ES OM once the charge lines have been submitted. In consequence, this causes as mismatch between the quantity/pricing in Teleservice charge lines and OM Order lines. Is there any way to make Qty field updatable on Charges tab. Also If this is not possible in standard product.