How to get exact data which matches regular expression

In pdf ,

I want to Create hyperlink on all numbers with dot (.) (1. , 2. , etc..)

This number will be in the starting of paragraph which has destination with same number with #

Note destination number with # can be on different page 

+++++++

Below is the code..

// Iterate through all pages of the PDF

for (var pageNum = 0; pageNum < this.numPages; pageNum++) {

  var page = this.getPageNum(pageNum);

  var pageText = page.extractText();

  // Use a regular expression to find numbers with dots at the beginning of paragraphs

  var numberRegex = /^\d+\./gm;

  var match;

  while ((match = numberRegex.exec(pageText)) !== null) {

    // Extract the matched number with dot

    var numberWithDot = match[0];

   /////////// Hyperlink and hyperlink destination code will come here .....

  }

}

++++++

Error

this.getPageNum(pageNum) is not a function

tried alternative, 

this.getNthPage(pageNum)

this.getNthPage(pageNum) is not a function

How do I exactly get the content of the page and match it with regex. Please help.

In the indesign script there is a doc.findGrep() function which makes life easier. How do I achieve this in PDF?

Thanks for the support.