Coding Spread strategies

Hi

I am trying to backtest a spread strategy on ctrader.

Unfortunately, I am struggling with the c# implementation in c-trader.

I want to achieve something like this:

Spread  = EURUSD - AUDUSD

If upper Bollinger bands of spread <= current spread value

Then sell market

If pos >0 then close pos

And vice versa

I would need to run 2 versions of this strategy for each symbol (first leg on EURUSD, second leg on AUDUSD)

Can you help me out or give some sample code?

Sincerely,

David Sanchez