I use xbmc to unpack the movies while streaming. So i dont have any mkv file to match the name from. Movie will typically be the.rock.1080.dts.the.best.edition.ever.rar
Is there a way to get XMM to look into the archive ?
Not really. While you could add "rar" to the supported file extensions under > Options > Device Scanner > File Extensions this will only get basic information (File Size) because neither XMM nor MediaInfo can handle archived media files directly.
There's nothing much to gain keeping movie files in archives because the compression gain is marginal. Maybe you can set the application which "delivers" the files to unpack the archives?