Creating a Write Off Waiver that will not affect the GL.(Writing off OLD Past Due)

I would like to ask assistance with creating a Write Off Waiver Item Type that will not affect the GL. Let me explain. From the Finance side of the house the old years worth of Overdue Accounts have been written off. But they have not been written off or cleared from the SA side of the house. We are trying to set up or create an Item Type that will not affect the original charge if we write it off now. How do we setup the GL Journal Se Chartfields to do this? Is there something in the Item Type