Produce a formula for Stochastic RSI using ONLY the High, Low, Close of a candle.

Hi, I need to produce a mathematical formula for calculating the Stochastic RSI using ONLY the High, Low, Close of a candle, and I need to write this formula for the stochastic RSI indicator in C#.
1. Stoch RSI = (RSI - Lowest Low RSI) / (Highest High RSI - Lowest Low RSI)

2. RSI Formula:
change = change(close)
gain = change >= 0 ? change : 0.0
loss = change
alpha = 1/y
sum = 0.0
sum := (x + (alpha - 1) * nz(sum[1])) / alpha

All formulas are in PINE SCRIPT. Entire PINE SCRIPT reference can be found at https://www.tradingview.com/wiki/

Is this something you might be able to help with?

Thanks