Over allocate entire LPN if quantity ordered is less than LPN quantity?

How to over allocate the entire LPN if the quantity ordered is less than the LPN quantity?

The item LPN/pallet quantity is not fixed and the item cannot be partial picked.

WMS enabled org and WSH:Overpicking Enabled = "Yes".

Example: Item RM34

LPN        QTY    RECEIPT DATE

U6643    3612    02/18/2015 09:04:48

U8601    3430    03/02/2015 10:27:29

U8604    3433    03/02/2015 10:27:58

Move Order 123 for 20 pieces. Need to allocate LPN U6643 for full 3612.

Move Order 124 for 4000 pieces. Need to allocate LPN U8601 for full 3430, AND U8604 for full 3433.

We cannot wait until the Move Order is being picked to override the Quantity to Pick because the next Move Order will allocate the same LPN.