It can certainly be done using the Subscripts and Superscripts utilities
However, you do need to think ahead a bit and probably the best series of steps to use would be
- Insert the Q = C
- Insert a superscript construct from the Superscripts and Subscripts gallery
- Select the dotted square after the C and insert a pair of brackets from the Brackets gallery
- With the dotted square inside the brackets selected, Insert the minus sign form the Symbols Gallery
- Put the selection between the ( and the - and then from the Superscripts and Subscripts gallery, insert the first item from the Common Superscripts and Subscripts gallery and then with the selection between the - and the ) insert a second of those items
- Replace both sets of x and y with the required letters and add the superscript n after the )