typedef struct
{
unsigned int     NumofParam;
double     ExperimentResults[3];
double     ValueofParamOne[3];
double     ValueofParamTwo[3];
}EXP_CONDITION;

int main()
{
EXP_CONDITION stInputs;
EXP_CONDITION* pstInputs;
pstInputs = &stInputs;

pstInputs->NumofParam = 2U;
EXP_CONDITION ExpNum[3];

/*assign values to Experiment 1*/
ExpNum[0].ValueofParamOne[0]=200;
ExpNum[0].ValueofParamTwo[0]=400;
ExpNum[0].ExperimentResults[0]=1000;

/*assign values to Experiment 2*/
ExpNum[1].ValueofParamOne[1]=210;
ExpNum[1].ValueofParamTwo[1]=440;
ExpNum[1].ExperimentResults[1]=2000;

/*assign values to Experiment 3*/
ExpNum[2].ValueofParamOne[2]=220;
ExpNum[2].ValueofParamTwo[2]=480;
ExpNum[2].ExperimentResults[2]=3000;

myfunction(&stInputs);
return 0;
}

myfunction(ExpNum);

void myfunction(EXP_CONDITION* expNum)
{
    double foo = expNum[0].ValueofParamOne[0];
    double bar = expNum[1].ValueofParamOne[0];
    double baz = expNum[2].ValueofParamOne[0];
    // ...
}