Can scrolling of values in a combobox field be disabled?

Notes client only. I have a form with a series of fields, each with possible values of Yes, No and N/A. I would like to implement each field as a combobox, because of the combobox’s neat, compact design (rather than as sprawling checkboxes or radio buttons, or dialog lists with inappropriately large dialog popups). Comboboxes work well, except that once a value is selected, it remains highlighted until the cursor is placed in some other field, and in the meantime its value can easily be changed accidentally if the user tries to scroll further down the form, as this actually scrolls the field values. Is there some way to disable the field values from being scrolled, and only allow selection of a field value via the drop-down box? Of course I can use a different type of field if I have to, but none of the alternatives look as good, are as convenient to edit, or fit so neatly in a narrow column.

Subject: Solved it myself

What I did was, ticked the combobox field’s ‘Run Exiting/On Change events after value change’ property, added some code to the field’s Exiting event to move the cursor to another field, and created another field nearby (normal editable text field but with text the same colour as the form background) into which the cursor is moved. So, as soon as the combobox value is selected, the cursor leaves that field and the form can be scrolled without affecting the selected field value. If the dummy field is placed immediately to the left (no spaces) of a combobox, the flashing cursor is not visible when placed in the dummy field, which is good.The ‘dummy’ field will be cleared - in case it happens to contain any invisible text - by its own Input Translation and On Exiting events.