Found something! Give it a try?
http://www.frictionalgames.com/forum/thr...#pid146245
Replace the ptest_lang/russian.lang in amnesia with this one in the .zip. It works for subtitles, but not buttons (those are dependent on the base_russian.lang), so perhaps try replacing the ptest_lang/english.lang with the one in the .zip. Then set the game language in the launcher to English rather than Russian. The buttons will be English, but the subtitles will be Russian.
NOTE: I do not speak Russian, so I'm not sure how accurate this replacement is when it comes to translation as it was fan-made.
Hope this helps you out!