I posted a file that contains all sparklines functions but does not install as an add-in.
The advantage, is that it is easier to share "dynamic" files and you probably can bypass the administrator right for installing a file in the "program files" directory.
Downside ? files are some 500Ko bigger due to the code.
To use the file, download it, rename it, use it as a regular Excel file
The file is available here.
Let me know if any issue.