Well test case development is a lot of the work by your testing team... half their day would be dedicated to the development of the cases and running them. There is software out there that can help stream line the process, but you also got to be aware that a lot of test cases are tailored specific to your software and what its individual needs are... saying that, it means there will still be times where your guys will need to write the test cases. Especially if it is something very specific and very unique to only your organization.
If you go to Google and type in "test case software" you can find a few vendors there. Most will not do this type of software for free and many won't even invest too much in open software for this area either. But you can find several programs that can help between 59 - 199 dollars. You will just need to find a few that you think may work and ask the company to provide you a demo to see before you buy.
You can try the following...
TestLogTestUpDevTestApTestThere are more with just a little searching. Enjoy!
"At DIC we be test case software ninjas!"