In order to incorporate the December number in the calculation, the SUM formula in the screenshot below must be "advanced" by one column. Is there a keyboard shortcut in Excel that will move this SUM function by one (moving to the right) once it is in edit mode to capture the value of the following column? I am seeking a keyboard shortcut to move the blue box to the right even though I am aware that I can do it with my mouse.
Naturally, I'm assuming the solution, if it exists, would be applicable to more Excel formulas than just SUM.
My Question:
While in Edit Mode in Excel, for any formula that requires an array for an argument (e.g. SUM, MIN, MAX, etc.), can I expand the existing array using a keyboard shortcut?
For example, in my screenshot below, I would like to expand EC64:EM64 to EC64:EN64 using just a keyboard shortcut. Is this possible? If so, how?
![Excel screenshot](https://i.stack.imgur.com/ebkfD.png)