XLL SDK install instructions
Install VS2008 express
Download the Excel 2007 XLL SDK from MSDN (Use your favourite search engine as the location is not static)
Install Excel 2007 XLL SDK (anywhere) (run Excel2007XLLSDK.EXE and choose the install location)
Copy xlcall.h from the SDK \ include folder to the \include folder within Visual Studio
Copy xlcall32.lib from the SDK \ lib folder to the \lib folders within Visual Studio
The include path is
(Eg: C:\Program Files\Microsoft Visual Studio 9.0\VC\include)
The lib path is
(Eg: C:\Program Files\Microsoft Visual Studio 9.0\VC\lib)
Alternatively you can add settings to Visual Studio to find them in any location of your choice.
The SDK also includes some useful wrapper functions to make working with the C API slightly less painful. These are Framewrk.c and its header Framewrk.h (note the spelling). To make them easy to include in many different projects copy these two files from the SDK folder to the Visual studio \include folder too .
You can then use
Instead of the more laborious and fragile
#include "C:\2007 Office System Developer Resources\Excel2007XLLSDK\samples\framewrk\FRAMEWRK.H"
This approach also works with the Codematic xll wrapper generator.
The Codematic xll demo uses these framewrk files, the current version includes them in the xll project folder.This is fine for occasional use. If you will be writing lots of xlls follow the above approach to put them in the include folder.