I'm looking for the product code that includes English, Spanish and German (more languages are welcome, but these three are the ones I'll actually use) for the E90
Looking for Spanish & English Product Code
Take a look in this thread: [How to] Reflash your Nokia E90 with a different firmware/language pack
You will need a EURO1 language pack firmware.
I guess selecting one of the firmwares which includes those countries would be the best bet for a suitable firmware 😊
EURO1 should contain languages similar to: English, French, German, Italian, Spanish, Portuguese
Good luck.