Problem with character set in Excel 2003 ?!

[nasko101]

Firstly, I'm sorry if my english is not on an appropriate level.
I have a serious problem with my work with Excel 2003. I'm opening *.wk1 files (Lotus 1,2,3) without problems. This filetype is supported by Excel, so the window "Text import wizard" (which appear after opening an unknown file for Excel, like *.txt file for example) does not appear. These *.wk1 files were created in MS-DOS in the past and were written on cyrillic alphabet, so they have different character set from the default in Windows. Afterward, once the file is opened, I can't find a way to change the character set and the symbols are incorrectly decoded and unintelligible. If there was some way to open the window "Text import wizzard" after opening the file, I could set the "file origin" and all should be OK, but I haven't found such option.
Please, help me to resolve my problem, no matter how. I just have to read this documents in Excel.
Thank you in advance.