Generate an SSH key, delegate a subdirectory for it, and add it to your SSH agent. Uses ED25519.

ssh-gen.bat

@echo off
echo : Configure
echo.
set /p SSHK_DIR="Subpath: "
set /p SSHK_COM="Comment: "
echo.

if "%SSHK_DIR%" == "" (
    goto INVALID
)
if "%SSHK_COM%" == "" (
    set SSHK_COM="%SSHK_DIR%"
)

echo : Generate
echo.
mkdir "%USERPROFILE%\.ssh\%SSHK_DIR%"
ssh-keygen -t ed25519 -a 100 -C "%SSHK_COM%" -f "%USERPROFILE%\.ssh\%SSHK_DIR%\id_ed25519"

if %errorlevel% == 0 (
    echo.
    echo Key created: %USERPROFILE%\.ssh\%SSHK_DIR%\id_ed25519
    echo.
    echo : Add to key store
    echo.
    ssh-add "%USERPROFILE%\.ssh\%SSHK_DIR%\id_ed25519"
    if %errorlevel% == 0 (
        echo Added successfully.
    ) else (
        echo Issues encountered when attempting to add to key store. Retry manually.
    )
) else (
    echo.
    echo Key creation failed.
)
goto EXIT

:INVALID
echo Invalid parameters. Exiting...

:EXIT