Excel for MacOSX - integration with C++ dynamic libs

I would like to call my own C/C++ code from Excel X on the mac. I have done this using Win32 for work and can generate DLL's using cygwin/gcc and MSVC. The Excel VBA interface in win32 requires a "Declare Function" like

Declare Function get_answer Lib "c:\bar\foo.dll" (ByRef Y As Double) As Integer

I would like to be able to do the same thing in Mac OS X, which I am a new switcher to. I have regular unix programming experience so I figured I could create a dynamic link library and such, and the process would somehow be simpler, because the Win32 DLL syntax is a bit arcane. But I can't find documentation.

Do I want a bundle? A shared lib? A framework?

Say I have the function in Win32 like

int get_answer(double *d) {
/* do something */
return 42;
}

I have "Mac OS X for Unix Geeks" open in front of me and I can create a .dylib or .bundle from this. e.g.

cc -O -fno-common foo.c -c
cc -dynamiclib -install_name libfoo.dylib -o libfoo.dylib foo.o

But I have no luck when I try accessing "/Path/to/libfoo.dylib" from within Excel X's VBA editor.

First guess is that I need to have a bunch of standard includes (e.g. in windows you use "windows.h") and some declares (probably not __declspec(dllexport) though). Finding details here is a bit tricky. The MSDN site has tantalizing mentions of "macintosh" here and there, but I can't find enough information to do anything.

Can someone post a pointer to some sample "hello world" code that can be built using gcc and linked with vba in excel? Start Free Trial