Theres programs that do that? cool!
I just use google with site:craigslist.org added at the end for eg - dp4b site:craigslist.org
This brings up everything ever advertised, so hit the the Search Tools button in-between the search bar and the results and click the anytime option and change it to day, week or month and instant relevant results! you can add the area in front too eg - nashville.craigslist.org
Recently i have discovered that search engines in general don't search for 3 letter terms/words, but it seems to work ok with - mopar 383 site:craigslist.org - for eg
Nice looking car with good options, 4bbl & 915 heads, would not pay that for it though