dll programming trace caller..

I am new to dll programming so my Q may be lame.I wanna know is there any way to trace the caller from a dll without changing the function parameter?For eg,i have created a dll test.dll in visual c++

#include "stdafx.h"

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
return TRUE;
}

int _stdcall sum(int a,int b)
{
return (a+b);

}

So if a process calls sum with 2 int values,is it possible to trace this process from the dll?

Thx in advance.