Monitoring MAc adresses

Hello,

I would like Spiceworks send an string text over IP TCP or UDP to the automation processor when new host are detected or leave the network.
Something like :

"
POST http://192.168.0.100:1234/Fing_monitor/connected_mac_adress_list_at_2012.11.14-PM9:25/FF:FF:FF:FF:FF;AA:AA:AA:AA:AA
"

I didn't find how to do it.
Could you help me ?

Many Thanks

Alex