If you are looking specifically for the audio files or soundtrack in high-quality format:
While these digital releases sometimes default to English audio, you can easily drop the original Spanish STRAT.DIR and audio language files into the installation directory to enjoy the full Spanish voice acting with modern plug-and-play stability. If you are looking specifically for the audio
Para descargar el juego de manera segura y legal, te recomiendo buscar ofertas en tiendas digitales como: If you are looking specifically for the audio
Finding a high-quality (WAV-tier audio) Spanish version of the 1998 classic Commandos: Behind Enemy Lines If you are looking specifically for the audio