Hi Ludy. If your client wants you to leave the formatting intact then I can't see any alternative to opening the file in Excel (or possibly another spreadsheet program) and editing the text in place, within the HTML code.
If your client just wants a translated text, and isn't concerned about what form it's in, then you could extract the text like this:
1. Select all the relevant cells in the Excel worksheet.
2. Copy and paste to a new text file. At this point you will still have the HTML tags included.
3, Save the text file and change its extension to ,html.
4. Open the file again, and it should now open in a browser, which will use the HTML tags to format the text, instead of displaying them.
5. Copy and paste the text to your word processor.
Alternatively, at step 4, you may be able to open the file directly in your word processor.