Storing data is not the same as presenting data. So, your field is still "bit" type and can store values: true/false, enabled/disabled, Yes/No.
I know, there are some differences between programming windows forms and MFC programming
], but it changes nothing in our discuss. Remember, only application's user interface (UI) is responsible for data presentation layer and control. Embeded mechanisms route user input commands (checked selections, button clicks) to internal functions that may update the application's data. UI controls (windows, edit boxes, checkboxes, etc.) are responsible for displaying the application's data after each update.