I would do this using three separate legacy form fields. This would require that the document be protected for filling in forms, which places severe restrictions on editing.
Those form fields could be formatted the way you want.
To do this in Word 2010, I would probably use Greg Maxey's tools.
Add Classic FormField Controls to Ribbon I especially appreciate the addition of the classic lock button to the ribbon.
Otherwise, it could be done in vba using a UserForm (custom dialog box).
Create & Employ a Userform