Looks like it's placed there by Documents To Go:

http://support.dataviz.com/support.srch?docid=12792

"dalkar" <dalkar@discussions.microsoft.com> wrote in message
news:A09681B3-C70D-46AF-AD1B-8A712C40033B@microsoft.com...
> I have an Excel add-in that is always checked when I open the add-ins -
> DVZXLAddin. Does anyone have any idea as to what this is?