In this OLD thread you will find a step by step process on what you have to do to add a unit, name it accordingly and make it unique with the Equipment Editor. It's a little different from Nikivdd's method, but it works and tells you what individual steps you have to take for the icon and unit to become visible in the playing of the game.
Or you can read below....................
The things to do:
1. Going to the Graphics folder and the unit section where you put the new icons, rename the icon you want to your chosen name.
2. Be sure to include the "_" between ALL spaces between any words or numbers that do not join together
3. When you go to the Equipment Editor, load the same Units folder you changed the name of the unit within
4. Select the unit you want to duplicate (say Panther G) from the game's standard units, then click on ADD UNIT.
5. Scroll to the bottom of the unit list and you will see a new Panther G unit of the same type with a NEW NUMBER
6. Click on that unit with the NEW NUMBER and make sure it comes up in the window naming the unit with the NEW NUMBER
7. Go to the Unit Image box and click on the image of the default Panther G in the box, you should be routed back to the Graphics folder you are using, but if it sends you to just the game file, go to the Graphics folder and go
to the Units section with your newly named unit in it
8. Scroll through the Unit graphics until the ICON you renamed shows up in the Unit Image box of the Equipment Editor
9. On the left side bottom near the "Add Unit" button, you will see "Commit Unit", click on this button and you will have created your new unit.
10. Check the Traits boxes to make sure you can purchase the unique unit and NOT HAVE IT GIVEN AS A BONUS UNIT, if you make a change, click on "Commit Unit" again. Do this each time you make a change in the
11. When you are done, click on the "Save" button at the bottom of the Equipment Editor box. Be sure that you are saving to the correct EQUIPMENT LIST file of the game in the DATA FOLDER. You are not going to save this
change in the Graphics Unit folder! Make sure of the place you are saving the change. It will prompt you to make sure you want to replace the Equipment File, and you do so say YES. This command also links the new
unique Icon you made to your new unit in the Equipment list. If you did everything right, when you use the unit in a game it will not show up invalid. If it does, you left something out of the process so recheck your steps.
12. If you want to change the default units in a scenario or campaign there is another procedure for this and it does not go through the Equipment Editor, you have to change the game defaults. The answer for that is in
the thread entitled "Common Questions"
IF you rename the icons themselves in the png pictures of the graphics folder of your game, be sure to put "_" between any space: IE: Panther_Gross_Deutschland. The unit will come up "invalid" when you go to the map to play otherwise (and for other reasons if you are not thorough in making changes in the Equipment Editor). Best to do this when you can focus and concentrate to not lose your train of thought while doing it until it is completed and checked.