How to achieve test automation using a test harness in Simulink Test?

I am a novice in Simulink, and I am trying to test a subsystem of a Simulink model using a test harness. I have created a test harness in which I manipulate manually the inputs of the component under test, then I observe and record manually the outputs in an Excel spreadsheet. The inputs are basically constant blocks, while the outputs are display blocks. Given some inputs, if the outputs are those expected, then the test has passed.

My question is how can I automate this manual testing?

I gather from the Simulink Test documentation that the Test Manager allows test automation. I see that a baseline/simulation test allows parameter overrides, which can be used in iterations. However, I wasn't able to figure out how to automate the use my of test harness.