Add an a trailing ma and a crossover alert to an existing indicator

I have an indicator (attached) called RSI_adaptive_ma.

I would like to add to the indicator a trailing ma of the indicator (with variable settings for the ma including period and type of ma) and to add an alert to the indicator when the  RSI_adaptive_ma closes either above or below the trailing ma for the first time.

Whilst the  RSI_adaptive_ma stays either above or below the ma, no alert; only when it closes anew either above or below the trailing ma.

Thanks