Two new tools are now available that help protect computers from Office 2003 files containing malicious software code. The tools are designed to help defend against Office "zero-day" attacks.
One tool, called Microsoft Office Isolated Conversion Environment (MOICE), protects users running Office 2003 and 2007 Office (but can't be used with previous versions) by converting Office 2003 binary files to the Office Open XML format blocking out malicious code in the process. Moreover, the conversion takes place inside an "isolated environment," which prevents malicious code from running on the computer.
The other tool, called File Block Functionality for Microsoft Office 2003 and the 2007 Microsoft Office system, gives system administrators the ability to define which file types can and cannot be opened by users incorporating the ability to block access to certain files when a specific threat arises.
Both tools are detailed in a security advisory (link below) which includes more information and links to the files as well as installation instructions.
http://www.microsoft.com/technet/security/advisory/937696.mspx