how to return indicator value to an array

Let's say I want to return the value of RSI into an array:

extern double Lots = 1;
double osfarray[10];
double rsivalue;
double ind1;
double ind2;
double ind3;
double ind4;
double ind5;

//+------------------------------------------------------------------+
//| expert initialization function |
//+------------------------------------------------------------------+
int init()
{
//----

//---- initializing of all array elements with 50
//- OSF Array 0 = Long 100 = short
ArrayInitialize(osfarray,50);

// indicators
iRSI(NULL,0,14,PRICE_CLOSE,0) return(rsivalue);

How can I do that?

Secondly, is there a way to hold the rsivalue in a variable and then do some calculation on it, creating another variable such as RSI VALUE + Calculation which is independent variable?

thanks.