Yes, but only if your device supports discrete PowerOn & PowerOff commands. Many devices support discrete power commands even if they are not on the original remote. You can verify that on your Harmony remote. Click the device button, select the device in question and scroll down the list of commands looking for the discrete PowerOn & PowerOff commands. If you find them, then using the Harmony Software interface, reconfigure the device power settings to use the discrete commands under Device > Settings > Adjust power settings > ... and select "A button on the remote for On, and a different button for Off". Else, you will have to use the Harmony "Help" button to re-sync the device.