Sales Orders with credit card information

Hi everybody

I wanted to know if it is possible to find if the sales order has a credit card number on it?

When i go to the Sales order screen, the table-field for credit card# is CCDATA-CCNUM

Now CCDATA is a structure, so if i have a Sales Order number and I want to check if there exists a credit card number on that Sales Order, how should it be found ?

Basically I am trying to modify the billing due list program to list on those Sales Documents which dont have a credit card number on them.

So from the Delivery document, I drill to the Sales Order number & now I dont know which parameter to check which would guarentee the presence of a credit card number for paying the amount on the Sales Order.

Kindly if someone could guide me let me know ASAP

Thanks

Vinit