Add batch file to compile using MSBuild. Just as a first step, not used by build.bat or build-ce.bat.

compile-msbuild.bat

@@ -0,0 +1,61 @@
+@echo off
+
+rem  Inno Setup
+rem  Copyright (C) 1997-2025 Jordan Russell
+rem  Portions by Martijn Laan
+rem  For conditions of distribution and use, see LICENSE.TXT.
+rem
+rem  Batch file to compile Inno Setup using MSBuild
+
+setlocal
+
+cd /d %~dp0
+
+if exist compilesettings.bat goto compilesettingsfound
+:compilesettingserror
+echo compilesettings.bat is missing or incomplete. It needs to contain
+echo the following line, adjusted for your system:
+echo.
+echo   set DELPHIXEROOT=C:\Program Files\Embarcadero\RAD Studio\20.0 [Path to Delphi 10.4 Sydney (or later)]
+goto failed2
+
+:compilesettingsfound
+set DELPHIXEROOT=
+call .\compilesettings.bat
+if "%DELPHIXEROOT%"=="" goto compilesettingserror
+
+rem -------------------------------------------------------------------------
+
+call "%DELPHIXEROOT%\bin\rsvars.bat"
+if errorlevel 1 goto failed
+
+cd Projects
+if errorlevel 1 goto failed
+
+if "%1"=="issigtool" goto issigtool
+if not "%1"=="" goto failed
+
+echo - Projects.groupproj
+msbuild.exe Projects.groupproj /t:Build /p:Config=Release /p:Platform=Win32
+if errorlevel 1 goto failed
+
+cd ..
+if errorlevel 1 goto failed
+
+echo Success!
+
+if "%1"=="issigtool" goto exit
+rem  Sign using user's private key - will be overwritten if called by build.bat
+call .\issig.bat sign Files\ISCmplr.dll Files\ISPP.dll Files\Setup.e32 Files\SetupCustomStyle.e32 Files\SetupLdr.e32
+if errorlevel 1 goto failed
+echo ISSigTool sign done
+
+goto exit
+
+:failed
+echo *** FAILED ***
+cd ..
+:failed2
+exit /b 1
+
+:exit