Which PVO we can use to capture the your price attribute on the sales order line from sales order?

We are trying on a customization on the order extensions. As a part of that we want to capture the your price attribute value on the sales order line before the order number is generated on the sales order. The condition is written to print the attribute upon save in the extension. The message is printed with value as 0 eventhough there is a value for Your Price attribute . Which PVO we have to use so that we can capture the your price on sales order or the base price that comes from the corresponding price list ?