Okay, finally after 10 years of silence this one is beaten. Well, at least partly.
I want to warn you immediately that you will not be able to change one thing:
Globals.
You will also need a Hex editor for this process. I suggest Hex Workshop as a very convenient and reliable program.
Changing all the other things is fine. Now, how is it done:
Step One
Download the map I provided. Extract it wherever you want, you will only really need one file from it:
SampleHeroPMap.kwd
You can delete the rest. The names are a bit weird and long, this is done on purpose, so you would know the approximate length of an allowed map name. You will need it later.
You also need the map HeroPool provided by DragonsLover below. Extract it into your DK2 Maps folder. You will need for the next step.
Step Two
Open the HeroPool map you just extracted and, now it's important: leave it open in the editor. Then, open an existing map or create a map you want. Do whatever you want with it. You will notice that in the Keeper's properties window, you will now be able to add heroes into the Creature Pool of the Keepers, a thing that would be normally impossible to do without the presence of the HeroPool map. Also note that Hero Portal is only supported by 4 Keepers maximum. You can make a 5 Keepers map, but you'll have to give him a normal creature portal, because DK2 does not support Hero Portal for 5th Keeper or more.
Save the map to your maps folder.
Step Three
Now, take the provided .KWD file, rename it to your map name and replace the existing .KWD file of your map. Here is when you'll need a Hex Editor. With the HE, open the renamed SampleHeroPMap.kwd file and scroll to the very bottom of it. You will see some lines starting with Data\Editor\Terrain and going to the very end to Data\Editor\Maps\SampleHeroPMapThings.kld.
Now, we will only need the lines that have the SampleHeroPMap name in them. Those start from Data\Editor\Maps\SampleHeroPMapPlayers.kld. Put the cursor behind the first letter (S) in the map name. Now, OVERWRITE the map name with your own map name, and add the suffix at the end. So, if it was Data\Editor\Maps\SampleHeroPMapPlayers.kld, and your map name is Goody, it will be GoodyPlayers.kld (no spaces, and don't forget the extension at the end).
Continue with the other 4 lines. Do not touch Data/editor/globalvariables.kwd.
Take note, these are case sensitive! If you have them in capital, keep them all in capital! You can't have one "Goody" and second "goody".
Now, if the name of your map is shorter than the original:
Put the cursor on the Hex column, so that it would be right after the last letter of your map name. For example, GoodyPlayers.kld is shorter than SampleHeroPMapPlayers.kld, so when rewriting you will get GoodyPlayers.kldayers.kld.
Now, keep adding zeros (0) till you cover all the unnecessary letters. It will appear as dots or squares on the right column.
DO NOT delete the letters! You will change the CHECKSUM of the file and it will not be recognized any more.
Save the modifications.
Step Four
Finally, delete the GoodyGlobals.kld file (in our example). You don't need that file anymore. Also, keep a copy of your new .KWD file if the editor would change it back after you save the map again.
You are done! Congratulations!
Post edited by DragonsLover