C++ Functions

xlcall.h

This is a header file that contains all the necessary data structures, constant definitions and enumerations that are used by Excel.
It also contains all the C API interface functions that are needed for information to pass between Excel and the DLL.
This file is part of the Excel 2013 SDK.
This file needs to be added to your project.

xlcall32.lib

This is a static import library that contains all the symbol definitions and function declarations that are implemented in the xlcall32.dll
This file is part of the Excel 2013 SDK.
It can be added to your project:
Configuration Properties > Linker > General > Additional Library Directories
(add the folder path)
This file is linked at compile time and the code is embedded into your solution.
At runtime it is implicitly linked to xlcall32.dll

xlcall.cpp

This is a source file that contains the code for the Excel12() and Excel12v() functions.
This file is necessary because these two functions are not exported by the xlcall32.lib or xlcall32.dll files.
This file is part of the Excel 2013 SDK.
This file needs to be added to your project and is therefore dynamically linked to the Excel callback.

Calling conventions

Any function that you want to call from Excel must include the modifier "__stdcall"

#define EXPORT cmment(linker, "/EXPORT:"__FUNCTION__"="__FUNCDNAME__") 
double __stdcall MyDllFunction(double Any) 
{ 
#pragma EXPORT 
} 

Other

functions might be
* in a cell formula
* named range definition
* conditional formatting expression

functions calls from a dialog box
special considerations for:
* Paste Special, Formulas
* Replace dialog box
* Insert Function (previously called Function Wizard or Paste Function)