Purchase Requisition from Work Order - Default Charge Account?

Summary:

When you create a purchase requisition from a work order in maintenance cloud, where do you setup to rules for controlling the charge account on the requisition

Content (required):

When raising a purchase requisition from a work order, would expect the default charge account to pick up values from the work order / equipment to be used in a mapping rule

Are these rules setup in : Procurement Transaction Account Rules / Manage Transaction Account Definitions? Have seen the Work Order: Mapping Rule in Cost Management, but which sub-ledger rule do you apply this too?

Is there a way to use a mapping rule to pick up the work order details, especially for the location of the equipment which typically would have come from the equipment.