title: Regexp to match every occurence after n occurences
body: <p>given some csv data, with unescaped commas in the final field like this</p>
  
  <pre>
  1, 2, 3, 4, 5
  a, b, c, d, foo bar
  a, b, c, d, Lorem Ipsum, dolores umbridge, something latin
  a, b, c, d, upcoming unescaped commas!, one, two, three, oh no!
  </pre>
  
  <p>I want a regexp to match all the commas after the 4th comma on each line so I can replace them with an escaped comma \,</p>
  
  <p>This is my terrible attempt so far which seems to return only the last occurence after the first n occurences.</p>
  
  <pre>^([^,]*,){4}([^,]*(,)[^,]*)*</pre>
  
  <p>For some context</p>
  
  <p>Some formats which claim to be partially compatible with csv formats like <a href="http://moodub.free.fr/video/ass-specs.doc" rel="nofollow noreferrer">ASS</a> assume that it's ok to have <strong>unescaped</strong> commas in the <strong>last</strong> field because the number of fields was registered when the header line was parsed.</p>
  
  <p>You can see this in the ASS specification</p>
  
  <blockquote>
    <p>The format line specifies how SSA will interpret all following Event lines. The field names must be spelled correctly, and are as follows:
    <code>Marked, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text</code>
    The last field will always be the Text field, so that it can contain commas.</p>
  </blockquote>
  
  <p>and here </p>
  
  <blockquote>
    <p>The information fields in each line are separated by a commas.
    This makes it illegal to use commas in character names and style names (SSA prevents you putting commas in these). It also makes it quite easy to load chunks of an SSA script into a spreadsheet as a CSV file, and chop out columns of information you need for another subtitling program.</p>
  </blockquote>
  
  <p>To be able to parse files like this, assuming you've already separated the data into "Chunks", I need to also escape all the commas in the last field to work with certain <a href="http://csv.adaltas.com/parse/" rel="nofollow noreferrer">csv-parser</a>s.</p>