The Unicode character code set defines a series of codes that enable you to combine diacritical marks, for example to type a letter and then put a dot over the letter. The code to place a dot above a letter is "0307." To put a dot over a letter in Word, type the letter, type "0307" and press "Alt-X" to invoke the diacritical combination.
Using Built-In Symbols and Characters
Many popular fonts, such as Arial, Times New Roman and Calibri, include letters with dots above them as standard characters in the font. To insert one of these font symbols in Word, choose "Insert" from the menu, "Symbol" from the ribbon bar and choose "More Symbols..." Select the font in the font selection box, locate the symbol you want to insert, click to highlight it and select "Insert."