Streambar SE pair Directv remote to this device is it possible?

If your tv model has hdmi-cec feature and it's turned on. Also, that the tv and Streambar SE recognize each other as cec device. Once these are done, just program the Directv remote with your TV brand's code, it will control the volume on the Streambar SE. 

No directv remote has a built-in code for Roku, and if it did it wouldn't have Roku cec commands mapped to volume and mute keys on the Streambar SE remote preset. But as I wrote above it isn't needed, just your tv code.