ADD Existing Harddisk to Guest

Just create a new vm, then rename newly created vm image to something like vm-id-disk-1.bkp.vmdk. Move vmware image to /var/lib/vz/images/vm-id and rename it to match newly crated vm config.
1. Rename vm-id-disk-1.vmdk to vm-id-disk-1.bkp.vmdk.
2. Move vmware image to /var/lib/vz/images/vm-id and rename to vm-id-disk-1.vmdk.
3. Start the VM.

Worked for me.