C-DLL-VBA to excel (strings)
 

Hello, I'm trying to connect excel to a C dll library (call C dll from
excel through the VBA). It works well for returning integer and double
values (see simple example below), but I can't seem to get it to
return strings (Note that the dll I am making I tested and it works
well elsewhere because when I link it to an exe it is actually
returing a string as expected). I am using MinGW gcc (so basically
only C) to construct my dll, so I don't have access to BSTR and other
cpp like objects/functions... Is there a way to make the C dll return
strings to excel? Thanks

DLL.c
#ifdef BUILD_DLL
#define EXPORT __declspec(dllexport)
#else
#define EXPORT __declspec(dllimport)
#endif
EXPORT int __stdcall add2(int num){
return num + 2;
}

COMPILE mydll.dll
c:\ gcc -c -DBUILD_DLL dll.c
c:\ gcc -shared -o mydll.dll dll.o -Wl,--add-stdcall-alias

IN VBA:
Private Declare Function add2 Lib "c:/mydll" _
(ByVal num As Long) As Long