I believe Excel stores data using cp1252
in reply to Mixed character encoding issues
I don't think that's correct.Excel is Unicode enabled by default.
Try it out by entering a character available in the Unicode domain:
download a free Japanese font available here ,install it, open a worksheet and do Insert>Symbol>find the font and click on a letter,save it and then open it again.The character should be there in its original representation.
Since MS has a twisted notion of Unicode, I consider that the excel file is saved as UTF16, which is what is considered Unicode by MS (while UTF8 is considered multi-byte)
my hunch is that you do some sort of double encoding, so I would suggest to decode the character from UTF16 to UTF8