See attached screen shot (caret)
ribbon.jpg
Left is a standard combo box control. You can select entries from the drop-down list.
On the right is an edit control with a "history" button. You can enter text, it makes auto-complete suggestions and you can show the history of previous entries with <Ctrl>+<Cursor-down> and the separate caret button. Could also be an other button or icon.
I could have used a combo box control with edit for that purpose, but unfortunately there are painting issues with combo boxes also displaying an edit control. I could not make this type of combo box working properly as an owner-draw control to match fonts and colors of the dark-themed ribbons.
Ah - I see.
Thank you for the explanation.