vbulletin 3.6.8 advanced PM system

Looking to limit PM communication between users based on their user group. More specifically: Vbulletin control panel -> Usergroup manager -> Private Message Permission Should get another option: PM Communication Allowed with usergroups and the field for usergroup ids that this group is allowed to communicate with Example: usergroup private is allowed to PM only to usergroup sergeants; usergroup sergeants is able to PM to privates and lieutenants… etc Finally, warning message should show up when someone tries to PM to unauthorized group: Based on your rank you are authorized to PM only to group1, group2, … In case of success will provide with several other vbulletin related projects. Thank you