I do not think that it is possible to configure an access port to belong to multiple VLAN.
Only trunck port can belongs to MultiVLAN with DOT1Q or ISL support.
However in 6500 you can have PVLANS.
In which you configure the port of the PC as promiscous port.(Primary VLAN)
Configire the remaining (required) ports with 2 different Secondary PVLANS (community/Isolated) mapped to same primary VLAN