Good morning,
Looking for a way to start a plug for video conference lights when the PC is running a certain program. How would I go about that ?
HASS.Agent.
Allows access to the entire WMI namespace. Write a sensor that evaluates true when that app is running on the pc. Then have an automation respond from that sensor.
Thanks ! Might be a bit too complicated for me … will continue to learn 
Make the link to the program on the computer a script that first sends a signal to HA and then start the program.
HA have many way to accept a signal, like a REST command or a webhook, just to mention two ways.