WDE 8.5 Customization, customize ToolbarInteractionBarRegion

I have to customize the WDE 8.5, in details i have a requirement to add a counter in the ToolbarInteractionBarRegion to evidence the Hold time. please find below and easy mockup of what i would like to do…inside the green box the counter to add

https://lh3.googleusercontent.com/-_pM3FWke9ZE/VV3b2IRbblI/AAAAAAAAXEc/NVYc4Jy8aaY/w577-h91-no/CustomToolbarInteractionBar.png

Is it possible? if yes can you help me?
Thanks,

Carlo

You could develop this?

Maybe not just where you want, but you can do it on the right side.