Forecast Consumption - Shipped Quantity

If we are looking to change our planning setup from a G planning fence rule to H planning fence rule for forecast consumption for certain items, is there a UBE that can populate the F3462 file with the appropriate shipped quantities for items we are changing to forecast consumption for shipments prior to the switch to the planning fence rule? If not, is there any recommendation on how to transition to an H (forecast consumption) driven item?