Support extension *.wk4 for Lotus 1-2-3.

I had used excel version 2003 in Lotus notes. Since then excel does not support extension *.wk4 for Lotus 1-2-3. I have now problem to import excel 2010 in Lotus. I have tried all the extension, tabular text and many options.
If there is anyone have faced the same problem or experienced with how to handle this please let me know soon.
