How to highlight segment signal line in Simulink?

Hi all,

I use find_system function for find all signal in untitled model as:

>> lines = find_system('untitled','FindAll','on','type','line')

lines =

  195.0822
  196.0822
  194.0822
  204.0823
  193.0822

Now I want to highlight 1 of segment as:

But, when I use hilite_system function, it alway highlight all of segments.

  hilite_system(lines(i)) % i = from 1 to 5

So, how can I highlight 1 segment only?

Thank you so much.