Here is the list of all controls supported by TestComplete for DevExpress as recognized components.
https://support.smartbear.com/testcomplete/docs/general-info/supported-technologies/controls/devexpress.html
This does not mean you CAN'T automate that control, just that TestComplete won't supply some of the "out of the box" wrapper methods that you would typically see for controls of this type.
You can attempt to add the control to your project in Tools -> Current Project Properties -> Object Mapping. This may work for you but, since the control is not natively supported, there may be some things that don't work well.
The alternative will be to examine the available properties, methods, etc., that are exposed to TestComplete and write your own custom wrapper code to perform the tasks you need do to. This can be code intensive but, once done, you will be able to automate around said control.
