Once again let me remind you that currently the HPS ACW games have the .map files locked out so that only the original files will work within a particular game engine. You can make your own MAP file and load it into the Scenario Editor, it will work fine there and you can create a scenario file with it. However when you attempt to start the scenario file in the game engine you will get an error message. The information provided here is done solely for those who continue to use the old Corinth 1.01 engine which does not lock out custom oob and map files. Unfortunately it also does not have many of the improvements to the engine that have been added since then.
Kennon Whitehead, a member of the ACWGC has written a Map Editor program that will produce maps that can be used with Corinth 1.01.
Before downloading it you should be aware of some things.
You will find Kennon's Map Editor program