How to append the results HTML output file on JMeter tests using Ant

I have the following issue.

I have 100+ Jmeter tests as separate files with the tendency to add more. Using Ant I have configured the results to come into a separate output HTML file for each test. So now when I have 100+ tests I get 100+ resulting HTML files. And I need to check every single one if the tests run OK.

My question is how to make the Ant append the results into one HTML file for all 100+ tests so I can view with a single glance that the tests run OK.

I guess I either need to modify the ..extras/build.xml file in Jmeter or modify the command line where I invoke my tests via Ant.

Thank you in advance.