You can create a Bash script, or a desktop files, containing the required variables/commands.
Example for a Bash script:
Save the file as whateverName.sh, make it executable, and you can now launch from terminal or right click probably, this script
For a .desktop file I guess it would be something like:
Name=Game Name Here
Comment=My Game description Here
Exec=WINEARCH=win64 WINEPREFIX=~/Games/W3 wine ~/pathToWitcherExecutable
I think you can have Terminal=true/false it shouldn’t break anything either case
Place the .desktop file in ~/.local/share/applications/ it should appear in your desktop menu now.
One better solution is to use Lutris, but this is a whole another guide by itself, check wikis/google/forum. Lutris is great to manage containerized Wine programs, each program in its prefix. You could simply ‘create’ an application in Lutris and configure it to use your existing prefix and files