4th group marking

[CplDixon]

Hello,some one know how to determine the 4th Group marking on a vehicle ? How can i know the number of my vehicle in the Company marching order ?
I know that in the HQ&HQS Co of my unit there are 54 vehicles(including trailers and semi-trailer),(there is a chance of adding 5 more vehicles). How can i determine if my truck is the 3rd,the 12th,the 30th ? I don't know
My truck is a DT 969A
I can tell of which platoon of this company is my truck
My truck is from the Transportation Section includes in the Service Platoon of the HQ&HQS Co.(Quite complicated)
All the vehicles are in the Service platoon of this company
39 vehicles in the Transportation Section
The rest are in the Equipement Section and in the Repair Section

My units is 9AAF 834E HQ-**

I got the TO/E 5-416 EAB HQ & HQS Co