Microsoft Office 2007 stopped supporting many file formats, including wks and dbf. So even if you have Access 2007 you won’t be able to save in dbf file format, if you still have Access 2003 you can.
Try OpenOffice 3.0.1 Calc. It’s part of a free open source Office suite that can read in Excel 2003 and save as DBF.
As a hint I recommed you set OpenOffice Options to save in MS Office format.
is free!
http://download.openoffice.org/contribute.html?download=bouncer&product%3DOpenOffice.org%26os%3Dwinwjre%26lang%3Den-US%26version%3D3.1.1
Best regards,
Rafael
P.S. You got to accept it, P3 is obsolete. Try using P3 Primavera Mail with Outlook 2007, it won’t work unless you trick the software default. As new Office and Windows updates surfaces more and more functionality will be lost and many in your company might be at risk of not even being able to access it.