how to aggregate a text file exported from another website into search results

Hi, the company i work for uses network solutions's eCommerce solution to sell products online and we have a separate main company website that is running drupal 6. the ecommerce site provides a link to a tab-delimited text file with current product descriptions and their urls. on the main website (drupal 6), we want the search results to include the content from the text file coming from the ecommerce site. so for example, on the main site when someone types the word "chair", the search results should not only include content from the main website, but also include the content from the ecommerce site. btw, the text file from the ecommerce site is the same file we send to google's search engine. any suggestions? A small caveat: I'm a bit of a newbie.

Thanks!!

-sul.