use vbslic.exe to mod vboxdd.dll and add slic record to it.
VBoxManage setextradata "VM name" "VBoxInternal/Devices/pcbios/0/Config/DmiSystemVendor" "System Vendor"
VBoxManage setextradata "VM name" "VBoxInternal/Devices/acpi/0/Config/CustomTable" "/path/to/table.bin"
