Loading stations

Before I get to my issue, I'd like to say that I work as an Operations/Ramp Agent in Berlin, Germany at TXL/EDDT. I get to walk around and go in the cockpits of 737-700/800 all day with Air Berlin. The way the aircraft is setup is with 4 loading compartments. 1 & 2 are in front, with CPT1 typically for crew bags at 15kg per piece. This is also not including in the DOW. If we have a dog or other animal, they might be placed in CPT 1 or 2.

CPT 3 & 4 are in the back. CPT3 is typically where all bags will be loaded. We take an average of the total weight by the number of bags to get our "per bag weight". If there is a full house, for trimming purposes, we will load 20-30 bags in CPT2. CPT2 can also be used for cargo.

The loadsheet has the individual compartment weight on it. The NGX however only has "forward" and "aft" loading in the CDU. Does anyone know if it's possible to get all 4 stations in the CDU, or would that be too complicated?

I've been flying actual routes with actual used PAX loads and CPT loading to see if my ZFW and TOW match... Which is close... But my DOW and DOI are off which results in a CG error for trim.

Any Ideas?