Office XP PIA's
For those that have applications that work with office, and unfortunately don't have Office 2003, but XP, you have the option of using the Office XP PIA's (Primary Interop Assemblies) to install on the machine for your application, so that you can use a .NET interface when working with the Office API.
To install it, you have to run the register.bat, which uses the gacutil to install them in the GAC. You should use the Visual Studio command prompt to install, but if you don't have access to it, you can copy it to the "windows\microsoft.net\framework\<version>\" folder. I installed them with the 1.1 version utility.
If you don't want to have to find all the DLL's to later delete, you can put them in a custom subfolder, then hack the register.bat file to include this subfolder in the registration. Once you have these installed, you reference the Office API in the COM tab, which then instead replaces this reference with the Office .NET PIA version in the GAC, automatically for you.