VLC starting from 1.0.0-rc1 let you configure the scrobbling to a single,
1) GUI way
Open the preferences and select "ALL" under "Show settings".
Then visit Interface => Control Interfaces
Check the checkbox for "Submission of played songs to last.fm"
Open Preferences > All => Interface => Control Interfaces >
Change the Scrobbler URL from post.audioscrobbler.com to what you need
VLC must then be restarted for these changes to take effect.
2) Geeky way
Open vlcrc file and look for scrobbler-url
Change the line to