Average entry price line in chart

I would really enjoy, and need, an average entry line in cTrader charts. 
To make sure what I mean :   If you open several positions of the same instrument, with different sizes at different times, 
you can calculate a certain price level and size which acts as if you opened all positions at that price.
FXCM Trading station standard has an average entry line like that.   I enjoy moving my stop loss to that level sometimes. 
Please implement this. 

Possibly add a button 'move stops to average entry price'.

thank you

(I tried searching for this in the forum and suggestions but I get swamped by 'moving average' posts)