Control Lines Length Individually as Nr of Curves Change

Hello everyone, Im currently working on a definition where a 2 parallel lines length is varied. These lines are then divided and from this points I create perpendicular lines. 

I evaluated these lines with a graph mapper and recreated them in order to be able to vary them.

Problem is I need more control on my variation, I need to vary the length of each line individually. I cannot use sliders, because as I increase the first 2 lines depth or z value, more lines are created, so I need more sliders, which are not created automatically.

Any ideas?

Thanks in advance.

Pd: I know my gh is messy but hopefully you will understand.