GetThisDLLName.cpp

#include "Win32DLL.h"
#include <iostream>

#ifdef UNICODE
#define tcout std::wcout
#else
#define tcout std::cout
#endif

EXTERN_C IMAGE_DOS_HEADER __ImageBase;

tstring WIN32DLL_API GetThisDLLName()
{
	//// and then, anywhere you need it:
	TCHAR  szDLLPath[_MAX_PATH];
	::GetModuleFileName((HINSTANCE)&__ImageBase, szDLLPath, _MAX_PATH);
	tcout << szDLLPath;
	return tstring(szDLLPath);
}

GetThisDLLName.h

#ifdef WIN32DLL_EXPORTS
#define WIN32DLL_API __declspec(dllexport)
#else
#define WIN32DLL_API __declspec(dllimport)
#endif
#include <string>

typedef std::basic_string<TCHAR> tstring;

tstring WIN32DLL_API GetThisDLLName();