just saw in Nuendo forum,similar topic… have we all missed it or what ??
maybe its not the same as with the range tool, but its possible to achieve similar results with the line tool,and the same as we wish with the square wave tool, make sure snap is off and use Ctrl+shift(by default) to have a horizontally constrained line. 
Agreed, this does create the ‘four nodes’ asked for in this thread. Nice find… I didn’t know it…!
Bob
(Though for me, its the ease of manipulation of that line you’ve created afterwards that counts. But that is probably another thread (Smart Tool stuff…?).! Oh, and here it is:-
Clip Gain Improvements - Cubase - Steinberg Forums - the first half of that GIF is nailing it, for me. And I see we’ve both commented in there already…! Nice.)