Have you tried asking on the Edain forums? (Are they still active?) We would love to help you here but the problem is we don't know how Edain has their code structured, so we can't really direct you to the proper place to make changes.
Look and see if Edain has an active forum, and try asking there.
If you can't find the answer by asking them, the wisest thing to do would be to learn what we are trying to explain, take that knowledge and then try to comb through Edain to see if you can resolve the matter on your own.
A quick crash course on modding:
EA compiles the massive amount of files into large files with the .big extension, the names of the files will give you an indication of what they contain. ini.big contains all the written code that the game uses. This .big file CAN be edited directly but within it is the ENTIRETY of the code in one massive file. This is messy and easy to get lost and cause crashes.
You should make your own mod. Make a folder, use FinalBIG to open and extract the contents of ini.big into your new folder. You'll see a directory like so '(your folder)\data\ini' and inside will now be individual .ini files separated instead of everything contained in the ini.big file. These individual .ini files can be edited.
When you make changes that you're interested in (a good first step is changing starting cash in playertemplate.ini) you can open FinalBIG again, and with it blank you can drag/drop the DATA folder that is in your new mod folder into FinalBIG, then save the file from FinalBIG to a new .big file "yourmod.big"
Navigate to your "My Battle for Middle-earth files" (or II or ROTWK), an example of where mine is located: "C:\Users\(my name)\AppData\Roaming\My The Lord of the Rings, The Rise of the Witch-king Files".
Place "yourmod.big" in this folder.
Copy your default game shortcut which you would normally use to launch the game. Paste a copy of it. Right click on the copy and go to Properties. In the TARGET line, you add -mod "yourmod.big" at the end of it. Here is an example of mine: "C:\Program Files (x86)\Electronic Arts\The Lord of the Rings, The Rise of the Witch-king\lotrbfme2ep1.exe" -mod "ProjectUndeadViking.big"
Hit OK and then launch the game using this new shortcut. If you did it correctly, your changes should appear in game.