I'm having trouble understanding your intent... for several reasons, including

• your formatting (put data inside <code> ...</code> tags so we can see what it really looks like)
  ... and
• Your paired, but (IMO) contradictory statements "Line 2 till Line n can be considered as irrevelant info for now. Line 1 till Line n is called a single "Subscriber loop""

Is the "n" in line n a variable number? Are lines 2- ..n really empty? Do they actually contain headers such as "line 1-", "line 2-"...? If they exist, are the trailing hyphens inconsistent as in what you posted?

Please clarify.

For a shot-in-the-dark, if the "Loop n" header consistently follows an empty "line n", then you have data which is probably susceptible to attack with a regex. And if the line-numbered data is more-or-less the way it looks here, then spliting on commas and combining (concatenating) the first three elements or a regex with captures nto AoAs might be a useful step one.