It will take some work.
First you need to learn a little on how to write the code that Mach uses.
Here is a link to something I made while trying to learn the basics.
https://www.machsupport.com/forum/index.php?topic=45397.0It is not hard once you get started.
To get to the Signal Script you need to go to Operator then Edit Screen.
On the left side of the screen under Screen Tree select the top level.
Under properties below that select the center icon (Events)
Next to Signal Script click on the code and a window will pop up with all the code in the Signal Script.
Make sure you made a backup copy of your Mach4 so if you mess up it is easy to start back over.