Cancel SO Order line in RMA

Hi,

I am trying to create RMA , sales and return order. (SO and OM)

I setup up P42025 processing option of Credit Memo tab -

1. Enter the status code to select when retrieving credit orders.	999
2. Enter '1' if the status code is based on the Last Status.  If left blank, the status code is based on the Next Status.
3. Copy the original sales order invoice date to the credit Order. Blank = Do not copy the original sales order invoice date. 1 = Copy the original sales order invoice date

I have sales order which as few sales updated (620-999) (900-999 for back order line) and 1 cancel line in it.