Hi,
I've used Proficy Historian, I wouldn't class myself as an expert though.
If I was tasked to do what you were asking I'd use the administrator tool to make sure the archive is installed (Click Datastore at the top of the administrator and it will show a list of the archives loaded) If the archive wasn't loaded, use 'Restore an Archive from' to load the archive into historian.
I do not believe there is an export to csv tool so you'll have to use the 'Excel Add-In', for example, to extract the data you want.
Hope this helps
Rich