I need to search the web for sites that are in our industry that use the same Adwords management company, to ensure that the said company is not violating our contract, as they have been accused of doing.

They use a tracking code in the template of every page which has a certain domain in the URL, and I'm wondering if it's possible "Google" the source code using some bot that crawls the code rather than the content?

For example, I bought an unlimited license for an image gallery, and I was asked to type the license number in a comment just before the script. I thought it was just so a human could look at the source and find out if someone paid, but it turned out that it was actually that they had a crawler looking for their source code and that comment. If it ran across the code on your site, it would look for the comment, and if it found one, it would check to see if it was an existing one. If not, it would first notify you of your noncompliance, and then notify the owner of the script.

Edit: I'm looking to index HTML and JavaScript only, not the server-side languages or Java.