There is a good white paper available that gives you invaluable information about 64-bit Office. Here are the download link,
Office Ultimate 2007 Activation Key, description,
Office 2007 Enterprise Serial clave, and table of contents. Compatibility Between the 32-bit and 64-bit Versions of Office 2010 Summary: For customers working with large amounts of data,
Microsoft Office 2007 Standard cl��gen, Microsoft Office 2010 is now available in a 64-bit version. This article discusses issues around the compatibility of the 32-bit version with the new 64-bit version and legacy 32-bit Office applications and their solutions. (12 Printed Pages) Introducing the 32-bit and 64-bit Versions of Microsoft Office 2010
Comparing 32-Bit Systems to 64-Bit Systems
Introducing the VBA 7 Code Base
ActiveX Control and COM Add-in Compatibility
Application Programming Interface Compatibility
Using Conditional Compilation Attributes
Conclusion
Additional Resources <div