You could achieve this using a CreationFilter, but it would be quite tricky. In a very simple case, where you know that your application is not using Application Styling and you know which Style the UltraToolbarsManager is going to use, then you could make assumptions about the color(s) and styling of the button and that would simplify things a bit. 

Based on your screen shot, which is apparently using Office2013 style, I whipped up a sample of how you might go about adding a single button to the header. If you wanted more than one button, or to dynamically change the button(s) at run-time, that would of course be a lot more complicated. 

My sample just uses a simple string as the context for the button and it creates a placeholder image using the first letter of the string. If you were going to do this in a real application, you would want an image with magenta in it and the magenta would be replaced by the ForeColor - which is what happens with all of the other system buttons in that area. 

Anyway, even this simple case was pretty complicated and required a lot of code. So please let me know if you have any questions. 

UltraToolbars_Header_Button.zip

I'm sorry to say this, but after investigating and doing some research about how to put a ButtonTool to the left area of the minimize/maximize/close buttons, this has been determined to be a product idea. You can suggest new product ideas for future versions (or vote for existing ones) at <https://es.infragistics.com/community/ideas>.

Submitting your idea will allow you to communicate directly with our product management team, track the progress of your idea at any time, see how many votes it got, read comments from other developers in the community, and see if someone from the product team has additional questions for you.

Remember when submitting your idea to explain the context in which a feature would be used and why it is needed as well as anything that would prevent you from accomplishing this today. You can even add screenshots to build a stronger case. Remember that for your suggestion to be successful, you need other members of the community to vote for it. You can also link back to this thread for additional details.

Thank you in advance to submitting your product idea.

Hello,

This is just a notice that we received your inquiry and that we are making an investigation.

When we have any update, I'll let you know. So, could you wait for a while?

Thanks in advance.