Sam, please feel free to email me in the future. I don't check cocoontech very often anymore.
It sounds like you have this part working:
http://www.eventghost.org/docs/short_manual/index.html
Macros are named containers that can hold Events to trigger the Macro and Actions to execute when the Macro is triggered.
For others, attached is a quick example of how an EG event does something in Premise.
But, since you really don't want to do something in Premise, but in EG, there are three approaches, all of which will involve some scripting:
1. use scripting under the "Computer_Home" object, by modifying the PythonCommand property. If I remember right, it is very easy to trigger EG events in Python.
2. use the Devices.CustomDevices.EventGhost.EG_Events.EG_SendEvent object via a script to send the event.
3. use Devices.CustomDevices.EventGhost.EG_Tasks to start the application via a script.
2 or 3 are the easiest since they don't involve python, but only vbscript in Premise.
I used option 3 to start media center for a while. However, I switched to using Charlie's media center controller so I deleted the code or I'd post it. The neat thing is you can even check Devices.CustomDevices.EventGhost.EG_Tasks and ensure SageTV is not open, before trying to execute SageTV (assuming it allows multiple instances, if not there's no need to do this). You can also add in code to maximize SageTV, etc... But it all requires vbscript.