Windows C++ Thread Parameter Passing

No, that's the only way. Just create a struct with the 2 data members and pass that as void*

#include <windows.h>
#include <stdio.h>

struct PARAMETERS
{
    int i;
    int j;
};

DWORD WINAPI SummationThread(void* param)
{
    PARAMETERS* params = (PARAMETERS*)param;
    printf("Sum of parameters: i + j = \n", params->i + params->j);
    return 0;
}

int main()
{
    PARAMETERS params;
    params.i = 1;
    params.j = 1;

    HANDLE thdHandle = CreateThread(NULL, 0, SummationThread, &params, 0, NULL);
    WaitForSingleObject(thdHandle, INFINITE);

    return 0;
}