Automating changing link to open an attachment

Thank you both. The link that @Thom Parker provided actually had almost the exact code I needed. I setup our authoring software to not include any kind of link, so it just outputs plain text, and this scripts finds the text and adds a square link around it. 

This works fine for something like "myfile", but ideally, I'd like the text in the PDF to look like "my_file.csv". However, if I set the script below to add a link to the text "my_file.csv" (ckWord == "my_file.csv") nothing happens. Based on what I read about the getPageNthWord function, maybe the function is breaking "my""_"file""." and "csv" into separate words, so won't find them. Any quick way to sort that issue? 

Also, there will literally only ever be onone instance of this text in the PDF, I've made a rather rudimentary break once it has found the string it is looking for, but I'm wondering if there is a more efficient way of doing it. Currently the script takes about 30 seconds to run when the strict is about half way through an 88 page PDF.

for (var p = 0; p < this.numPages; p++) {
    var numWords = this.getPageNumWords(p);
    var foundit = 0;

    for (var i = 0; i < numWords; i++) {
        var ckWord = this.getPageNthWord(p, i, true);

        if (ckWord == "portslist") {
            var q = this.getPageNthWordQuads(p, i);
            // Convert quads in default user space to rotated
            // User space used by Links.
            var m = (new Matrix2D).fromRotated(this, p);
            var mInv = m.invert();
            var r = mInv.transform(q);
            r = r.toString();
            r = r.split(",");
            var l = addLink(p, [r[4], r[5], r[2], r[3]]);
            l.borderColor = color.blue;
            l.borderWidth = 1;
            l.setAction("this.exportDataObject({cName: 'portslist.csv', nLaunch: 2})");
            foundit = 1;
            break; // Exit the inner loop
        }
    }

    if (foundit == 1) {
        break; // Exit the outer loop
    }
}