/Shadow=ShadowId /ExposeUsing=LetterDirSpecOrShare /SharePath=SharePathDirSpec - Exposes an existing shadow copy volume through ...

%1 %2 /Shadow=ShadowId [/ExposeUsing=LetterDirSpecOrShare] 
    - Exposes an existing shadow copy volume through a share name or a mount 
    point.  If LetterDirSpecOrShare is specified, the shadow copy is exposed
    through a given drive letter, mount point or a share name.  If it is not 
    specified, a default share will be created and a name will be given upon 
    completion.  To expose through a drive letter, LetterDirSpecOrShare must 
    be in the form of 'X:'.  To expose through a mount point, 
    LetterDirSpecOrShare must be a fully qualified path starting with 'X:\', 
    and must point to an existing directory.  To expose through a share name, 
    LetterDirSpecOrShare must consist of only valid share name characters, 
    i.e. SourceShare2.  When exposing through a share, the whole volume will 
    be shared unless SharePathDirSpec is given.  If SharePathDirSpec is 
    given, only the portion of the volume from that directory and up will be 
    shared though the share name.  The SharePathDirSpec must start with a 
    - The only types of Shadow Copies that can be exposed are the 
    DataVolumeRollback shadows.  Shadow Copies that have the 
    ClientAccessible type cannot be exposed.
    - The Shadow Copy ID can be obtained by using the List Shadows command.
    When entering a Shadow Copy ID, it must be in the following format:
    where the X's are hexadecimal characters.  

    Example Usage:  vssadmin Expose Shadow 
                            /ExposeUsing=SourceShare2 /SharePath=\sharedpath