If you mean you should edit spreadsheet in .xls format - It's impossible to edit it in wordpad. If your spreadsheet is saved as .csv or .txt file, you can open and edit it.
If you need to edit .xls spreadsheet I see 2 possible ways:
1) Download and install either OpenOffice
(free) or MS Office
(trial version), then open your spreadsheet there.
2) Upload spreadseet to gmail.com using 'google docs' document upload, then you can edit your spreadsheet and save it locally.
Hope this helps.
If you can't download openoffice or use gmail.com for spreadsheet editing, you can use wordpad to create .csv file. Every line in this file corresponds to spreadsheet's row.
In one line you can separate fields with a ',' and enclosure them in double quotes '"', then such 'values' will be treated as fields in the row.
Ask me any further questions if you have.
Edited by Arty on 10/17/2010 at 9:32 AM EST