I am using Apache JMeter to load test a web application. JMeter has an XML file format for storing load test configuration information. I wanted to system test as well, and needed to generate a large number of unique URL hits. Rather than using the clunky UI to add them, and getting carpal tunnel from it, I analyzed the XML file format and split it up. Then I put tokens (XXXTIMETOWAITXXX) in the appropriate places, and used an Excel generated CSV file to drive perl to assemble the pieces of text into a valid JMeter config file.
Well, what happened next? I needed some way to generate a larger number URLs than Excel would be pleasant to handle? Again, perl came to the rescue, making it easy to generate umpteen lines of correctly formatted CSV.