How to run original Z: Steel Soldiers (2001) through Steam client

A guide to help everyone who wants an authentic Z:SS experience by running an original build of the game and also wants to track the time spent on it using the Steam client.

Intro

Let's preface this by saying that the usual method of running external executable through custom command line like:
"path/to/folder/game.exe" %command%
didn't really work for me, because for this particular game it returns an error stating it cannot find 'zsetup.exe' file, even though the file is clearly there in place.

So here's an alternate way of linking a different Z2 executable, without resorting to an external application.
This method have been tested on Win10 and it involves creating a small BAT script as well as leveraging iexpress tool that is part of default Windows package.

Main section

- First of all, install your original copy of Z2 on your drive. Apply any required patches to make it the whatever version you want.
- create a new .txt file on your Desktop and put the following lines in:

cd C:\Program Files (x86)\The Bitmap Brothers\Z Steel Soldiers\Bin
z2.exe

(the 1st line is your path to a folder that contains Z2.exe; the original, not the Steam version of the game)

- save this .txt file and close it.
- now, convert it to a .bat script file by renaming it to something like 'ZSS.BAT'
- run this ZSS.BAT file to make sure that it launches the original Z2 installed on your machine
- move this BAT script to the Steam folder where the Steam version of Z2 is located ('C:\Program Files (x86)\Steam\steamapps\common\Z2')
- click on Start menu and search for 'iexpress.exe' file that should be preinstalled on your system
- once it opens up choose 'Create new Self Extraction Directive file' and click Next
- most of the time just keep all the default options selected going forward from now on
- for 'Package Title' choose your name for the package, it doesn't really affects anything (I named it 'Z2')
- once you reach 'Packaged files' section, click on Add and find your BAT script file (which now should be located in a Steam game folder), then click on Next
- on 'Install Program to Launch' section put the following line in 'Install Program' text box:
cmd /c ZSS.BAT
(where ZSS.BAT is the name of your BAT script file)
now click on Next
- go to your Steam game folder ('C:\Program Files (x86)\Steam\steamapps\common\Z2') and rename 'Z2.exe' to 'Z2_backup.exe'
- go back to iexpress window and keep choosing all the default options until you arrive at 'Package Name and Options' section of it
- here click on Browse and go to your Steam game folder (where eventually all the required packages and executable files will be created), name executable file that will be saved as 'Z2.exe' (it will serve as a replacement for the default Z2.exe which Steam launches every time)
- after that follow all the default choices until the process completes
- Try to launch Z2 through your Steam Library, it should launch the original Z2 now while still keeping track of time you spent on the game.

After all is done

After all is done you should end up with a bunch of newly created files in your Steam game folder:
- ZSS.BAT (bat script you created)
- *.SED format file (like Z2.SED, depending on how you named your package in iexpress)
- new Z2.EXE executable (while Z2_backup.EXE is the one initially created by Steam)

If it doesn't work as intended review all the required steps and make sure you didn't accidentally skip anything.
Also try to make the new executable Z2.exe file to be compatible with WinXP SP3 by going to file properties and checking the WinXP compatibility.

If something went wrong with resolution, framerate, etc. it's highly recommended to use dgvoodoo2 library to configure all the graphical settings.
In dgvoodoo2 you can set custom resolution, force VSync, add antialiasing, etc. (but don't expect it to magically change the aspect ratio, Z2 only supports 4:3 as far as I know).