Harmony Hub: send single command

[MichelKesin]

I have a Logitech Harmony Hub with some activities like 'watching tv', 'watching Netflix', 'play radio'. I also have an infrared controlled curtain rail. On my remote, I have added the curtain device to every activity and a keypress on the remote gives the right signal. I want to automate this rail so that the curtains open every morning at sunrise and close at sundown. I can do this by making an activity and add a timer in Domoticz to do it. so far so good. The problem occurs when I am watching tv and it's sundown. This curtain activity starts which makes my other activity stop (turn of the tv and receiver). Is there a way to have a trigger just one command from Domoticz via the Remote Hub which doesn't influence the current activity.