JS for adding vertical line to matrix

Hi all, I am not well-versed in JS. However, I found some JS code online to add a vertical line to the qualtrics matrix, e.g., to set apart the "NA" option from other options (see code here: https://gist.github.com/marketinview/cd5d385d8803124078a0
This code works for me when I implement it, but it stops working when I enable the "repeat headers" option. Any help on how to adapt the JS code so that it works with the "repeat headers" option enabled? Code is below:
Qualtrics.SurveyEngine.addOnload(function() {
var q = jQuery("#"+this.questionId);
var cl = q.find('td.ColumnLabels:first');
if(cl.length > 0) cl.attr('colspan', cl.attr('colspan') - 1);
if(q.find('div.desktop').length > 0) q.find('.last').css("border-left", "1px solid #BBBBBB");
});