I'm not sure what you are after here. Normally you would create a customer table, then either have a billing address and a mailing address in that table, or more commonly, an address table with a look up to the customer table, and some field that tells you whether the address is for billing or for shipping, or both.
What is the table structure you are using?
On your data entry form, when the check box is checked, you can have it disable the controls for a seperate shipping address.
Look it up at: http://wrox.books24x7.com