Thanks Stonewall, you are right only changing the cities.inc doesn't help.
OK, let's do it the 'right' way.
Example: Let's change the city level of Washington DC to 10 for the April 1861 scenario.
1. Open the [font="Courier New"]AACW_Setup1861_April_Campaign26.xls[/font] from the AACW DB.
2. Change the city level on the cities tab.
3. Save the file as csv. (AACW_Cities1861_April_Campaign_Test.csv)
Don't forget to set the correct export filter settings.
4. Change the scenario name on the setup page, so the original scenario will no be overwritten (1861 April Campaign Test.scn).
5. Edit on the setup page the name of the cities inc-file to a new name. (CitiesCampaignA61_Test.inc)
6. Change also the sting alias for the scenario name so that you can recognize your new scenario in the scenario list (str1861ACampaign2DispNameTest).
7. Save the setup page also as csv-file. (AACW_Setup1861_April_Campaign_Test.csv)
8. Open the [font="Courier New"]LocalStrings_ACW25e.xls[/font] and add your new string there.
9. Save the modified string-file as csv (LocalStrings_ACW.xls) and copy it to the game directory ...\AGEod's American Civil War\ACW\Settings\
Overwrite the old file. (Save a backup before)
10. Open the csv-splitter, 'Setup,Events' tab and create a script from your setup file (AACW_Setup1861_April_Campaign_Test.csv).
11. Copy the created 'Script.ini' to the game directory '...\AGEod's American Civil War\ACW\Scripts\'
12. Go to the events folder and create a copy of the file '1861 April Campaign.sct' with the new name '1861 April Campaign Test.sct'. The reason is that the game will search for an event file with the same name as the scenario file. As you created a new scenario with new name the corresponding event file was missing. The original one from the April 1861 Campaign should be ok.
13. Create the cities.inc file with the csv-splitter.
Rename the file to 'CitiesCampaignA61_Test.inc' and copy it to the game directory '...\AGEod's American Civil War\ACW\Includes\'
14. Start the game. As soon as the load-screen appear press 'F9' once. In the upper right corner 'Edit mode ON' will appear.
Do nothing. The main menu will appear for a short while then your new scenario will load automatically. If you did something wrong (or I explained something wrong) an error message will appear. But normally your scenario should just load.
15. Press 'ESC' and save the game. The new scenario will be written.
16. Exit the game and start it again. If you choose 'New Game' your new scenario should be in the list and if you open it Washington DC will have city-level 10 now.