I ran in that very problem, when I revised the history files of EU3. Without proper programs you simply cannot save text outside of Western European Windows-1252 encoding, which let'd you ignore other languages. Sad, but true.
I have a very easy solution to this issue if you use Notepad++ and I've attached my Russian Polish text converter. Here are the steps I do (these are in the Russian Polish text converter).
*****************************************************************************************
* Use this file to take Russian and Polish translations (from web) and convert it to *
* ANSI with no character sets (default, what is required for AoD language support) *
*****************************************************************************************
For Russian:
1. Before pasting any text, ensure that the Encoding is set to Cyrillic, Windows-1251
2. Paste the Cyrillic text.
For Polish:
1. Before pasting any text, ensure that the Encoding is set to Central European, Windows-1250
2. Paste the Polish text.
For All:
3. Save the file, if prompted
4. Go to Encoding, Character Sets, Western European, Windows-1252
5. Take the converted text and paste it into the AoD file
I then have another Notepad++ text file (Working Event) that I use to paste translations from Google Translate into a HOI/AoD tech_names.csv file. I can just double-click the language name with the translation from Google or, if Polish or Russian, do the encoding first then double-click the language name.
1. I start with this:
2. Then I select and copy the following text
3. Paste that text
4. Now all I have to do is copy the translations from Google, double-click the correct language, and paste (except for the Russian and Polish which is 1 additional step as shown above). The end result is this:
5. And then I just paste the entire line into the tech_names.csv file. Notice that I don't overwrite the component or tech names.
These two files make translations and proper encoding easy. I also use the steps for any files (scenario_text.csv, extra_text.csv, models.csv, etc.) that require translations.