The addin is currently unsigned.
I downloaded this, exited my running MSVC++ 2008, installed the .vsi, and re-ran MSVC++ 2008, but I don't see the buttons on the toolbar. I see "MatchOptionsCommands" on the "Tools\AddManager..." ...
https://code.msdn.microsoft.com/Thread/View.aspx?ProjectName=vsmatchoptions&ThreadId=508 "The one thing that's missing is the "match regular expressions" button."