A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
You most likely have a ScrLck key on your laptop/netbook, but it is used in conjuunction with the Fn key and is noted in blue.
Alternately, use the On-Screen Keyboard and click the ScrLk button in the lower right. Click Start or tap the Windows key and type osk then hit <enter> to open the On-Screen Keyboard.
Addendum: right click Excel's bottom status bar and put a check beside Scroll Lock to get a scoll lock indicator on the left side of the status bar.