You repeat the question that many people do not understand.
You can describe in more detail your desire?
You can code such easily .
Here's some tip: Let's say you want the ratio of the highs, for example.
Then you write:
symbol1 = "EURUSD"; symbol2 = "USDCHF",
double value1= iHigh(symbol1,0,i);
double value2= iHigh(symbol2,0,i);
go here: http://docs.mql4.com/series/ihigh to learn iHigh, iLow, iOpen, iClose.
then you calc :
double LineValue= value1/value2;
You draw the line you want using the LineValue.
I know , I know, I know you want to say it's not so easy.
But yes it is. Just look around for an indicator that draws lines and gut it out. It's the way you learn.
or look here to learn : https://www.mql5.com/en/articles/1503