forecast of RSI

Hi all,

I create easy indicator:
fer = (RSI(15)+RSI(20))/2;

I would like to know C price next day if I suppose
fer will be 50.00;

I know code below:

Value = 50.00;
WildPer = period of RSI;
ExpPer = 2 * WildPer - 1;
AUC = EMA( Max( C - Ref( C, -1 ), 0 ), ExpPer );
ADC = EMA( Max( Ref( C, -1 ) - C, 0 ), ExpPer );
x = (WildPer - 1) * ( ADC * Value / (100-Value) - AUC);
RevEngRSI = IIf( x >= 0, C + x, C + x * (100-Value)/Value );

...but I spend a lot of time for adapt to my fer indicator.

Could somebody help please ??