Remove 3d-lines (from coordinate systems) that do not follow a specific path

Hi, I am having problem coming up with a solution to remove 3d-lines do not follow a specific 3d-line path.

For example, let's say I've created 200 lines that need to follow an L-path in an arbitrary 3d-coordiante system. I have the XYZ coordinates of these lines (and I can plot them using 'plot3()'). However, sometimes these 3d-coordinates deviate from the L-path and follow an incorrect C-path. I need to remove/filter-out these lines but keep the others that follow my specific L-path even though they might be shorter or longer.

What I've tried:

I tried using the 'cluster()' function, compute the median of each line, compute the eucledian distance from every 3d-line median coordinate (using 'pdist()' ) and group these lines into X number of categories based on their distances to the mean (and remove those that I don't need). However the problem here is that I don't know the number of X categories (usually to include as the incorrect C-path (or other random path that happen by chance) changes every-time I generate another set of 200 lines. I I generate over 100 sets of 200 3d-lines so manually looking at all of them is not a viable solution.

Thanks in advance for your help (I hope my explanation makes sense), Rodrigo