ecco una piccola guida in inglese su come settare di default salva i files con il formato ms office....
OpenOffice reads and writes Office 2007's default .docx and .xlsx XML file formats. But the older .doc and .xls formats are still the ones most often used. I suggest that you make the classic Office formats your defaults in OpenOffice. To set .doc as the document default, for example, open any OpenOffice program and do the following:
Step 1. Choose Tools, Options;
Step 2. Select General under Load/Save;
Step 3. Click Text Document under Document type in the Default file format and ODF settings section;
Step 4. Choose Microsoft Word 97/2000/XP in the Always save as drop-down menu and click OK.
To make .xls the default worksheet format, open the same dialog box and follow the same steps, with the following differences:
Step 1. Choose Spreadsheet under Document type in the Default file format and ODF settings section;
Step 2. Choose Microsoft Excel 97/2000/XP in the Always save as drop-down list and click OK.