reading a long long type _RecordsetPtr C++

Question

I am getting a long long type returned from my oracle function and I am trying to parse it using the below code

// pVal holds the output of function
pTempRS = (_RecordsetPtr) pVal;
pTempRS->Fields->GetItem((long)0)->Value.lVal;

The problem is it is overflowing therefore it works fine when the result returned is in INT_MAX range(~10**9) but negative value is show in case of value returned from function is greater than INT MAX range. Can anyone suggest what I am doing wrong?