How to Use Attracta SEO tools - when you can't add to robot.txt file?

I use a product called Attracta that helps push your sites out to the search engines and it uses the robot.txt file to do this with the addition of one line. This really helps increase your visibility and has some tools which look at links, length of your descriptions...and other things that affect SEO. I read all of the threads and notice you cannot modify the robots.txt file and I do understand what it does with indexing. It seems to notice that there is something there as it says it finds the following:

User-agent: *
Sitemap: http://www.asmallbusinessconsultant.c...
Disallow: /classes/
Disallow: /definitions/
Disallow: /templates/

I need this line added to the bottom of robot.txt file.

sitemap: http://cdn.attracta.com/sitemap/78269...

There should be a way to do this - otherwise it keeps you from utilizing some SEO tools like this to help you increase your traffic. Is there a way around not having access to the robots.txt file?

Karen