Blocking traffic between VLAN's on PowerConnect 6224

I configured my PowerConnect 6224 like this:

 VLAN 201 ip adresse 10.90.0.2 (network adr: 10.90.0.0 / 24)

VLAN 301 ip adresse 10.168.11.2 (network adr: 10.168.11.0 / 24)

VLAN 302 ip adresse 10.168.31.2 (network adr: 10.168.31.0 / 24)

VLAN 401 ip adresse 10.168.12.2 (network adr: 10.168.12.0 / 24)

VLAN 402 ip adresse 10.168.32.2 (network adr: 10.168.32.0 / 24)

VLAN501 ip adresse 10.168.10.2 (network adr: 10.168.10.0 / 24)

VLAN 502 ip adresse 10.168.30.2 (network adr: 10.168.30.0 / 24)

 The routing works great, but I need to configure some restrictions for VLAN 301 and 302. In both of these VLAN I want them to able to ping only the local subnet and 10.168.10.5 (our Internet proxy server). How do I configure de 6224 to prohibit VLAN 301 and 302 to be able to access only the Proxy server. VLAN 301 and 302 are public access WiFi for our employees.