Well I finally got there correct syntax was
Function PlayVlcPlayer(pstrVlcfile As String)
Dim strVlcPlayer As String
strVlcPlayer = Chr(34) & "C:\Program Files\VideoLAN\VLC\Vlc.exe" & Chr(34) & " --fullscreen " & Chr(34) & pstrVlcfile & Chr(34)
Shell strVlcPlayer, vbMaximizedFocus
'...