You will probably find English in one channel and the Russian in the other. If this is the case, then use VirtualDUB to save out audio, (see DivX to VCD tutorial in Movies Tutorial section) then use your favorite Audio editor (Goldwave, Sound Forge, etc) to move the English to both L & R channel. Save out as a WAV, merge back into AVI with VirtualDUB and save AVI again.