How to Include an Ampersand (&) in an Excel Header or Footer
If you type "Header & Footer" or "Smith & Jones" into and Excel Header or Footer (whether you use the dialog box or type directly into the space), Excel will appear to delete the ampersand when you return to the main worksheet.
Why does Excel do this? The ampersand is a reserved character in the Excel Header and Footer, as in "&[Date])" which is a field code that translates into the current date when the document is printed. Most of the icons on the Header/Footer tab of the Page Setup dialog box insert one or more field codes into the Header or Footer you are creating.
To have Excel insert that convivially conjunctive ampersand, simply type two ampersands together without a space. "&&" is reserved to translate into a single "&" in this context. "Smith && Jones" translates into "Smith & Jones" when you return to the main worksheet, and it will print properly on paper too.
Submitted by Denise Ash, from a tip in the Savvy e-newsletter