Header Macro with a list box

Hi friends,

Im looking for the code to develop a macro which will give me a pop-up of a list box before Save As option. The list box will have the types of header for data classification. Once I select a type of header, the same will be set for that particular excel file.
eg:
1) I select the Save as option,
2) List box pops up
3) From the list box, I select Internal Confidential
4) Header is set as "Internal Confidential"
5) The Save as option widow pops up

Why I need this....

I have several types of header...so every time I have to change the existing header/ add a new header

Thanks