Retrieve data from Alert window & retrieve an object from an external .ex4 indicator

I have an expert .ex4 that reads several indicators .ex4 (even if are not present in a chart) and produces alerts on Alert window.As soon as an alert pops up I need to open a trade with data contained in the alert (cross, direction, TP). The SL has to be retrieved briefly opening the cross in the required timeframe and to check for last box that it has drawn on chart. The level where is displayed this box is the level of SL price.

So:

this EA open Alert window with a new line 

name of EA         Cross       Timeframe      Direction         number of pips (to be converted into TP price)

XYZ EURUSD        M30        BUY 24.7 pips

The EA I request has to open this trade and for SL has to check for the indicator on EURUSD M30 chart where the last box has been placed and this is the stoploss  price level of operation.