Update prices on Sales Order items

Hi,

We have a business scenario where we need to update Prices in SAP Business byDesign in all my sales orders. Here's a brief description: In our system sales orders are created with provisional prices (determined based on price lists maintained in the system). At the end of the month on a fixed date, the users upload new price list for all items. Now to update each sales order to reflect the new prices, the user needs to manually enter each sales order and click on the update pricing button. As the sales order volume every month is very high (thousands) for the business, it is not a feasible option for the user to do this for each sales Order.

My question is whether there is a way the update pricing functionality can be automated on a fixed date of the month?

Both standard or any custom development is highly welcome.   

Thanks in advance,

Ankit Periwal