Yes, you can do that, and it is easy to do and a great introduction to customizing your Quick Keys Dial. 

First, you will need to open your Settings Panel to access the Dial controls on your Quick Keys.

The image to the right shows what the Device window would look like if you had both a Pen Tablet and Quick Keys.

If you only have the QUock Keys, that is all you would see in the Device Window.

[1] Select Quick Keys from the Navigation column on the left.

Once you select My Quick Keys from the navigation column on the left, the Quick Keys panel will load and look similar to the image on the right.

[2] You will want to ensure that the Yellow Globe has the Yellow Bar under it.

[3] Then select the Dial selection or mode to which you want to assign the Volume control to. In this case, I chose mode 1.

Once you select the mode, [4] Click on the selection drop-down box, {5] and select Keystroke. 

[1] You will need to name this action. I called mine Volume Control. This will be displayed on the Quick Keys OLED when you press the Dial button.

[2] You will need to press the keys on your keyboard that control your volume. On my keyboard, it is Fn+F2 for Volume down and Fn+F3 for Volume up.

Once you have pressed Fn+F2, the phrase Volume Down will appear, and once you press Fn+F3, Volume Up will be displayed.

You can enter these in any order, Volume Up in the top field and Volume Down in the bottom field.

[8] Then Click OK -

Now you have the Volume Control set to your Quick Keys.

If you would like to add some fine-tuning to the Volume control, you can do that here.

[9] Dial Sensitivity allows you to adjust the speed at which the Dial reacts to the Dial rotations.

[10] You can change the color and [11] the brightness of the colors.

[12] Click OK, and you are set up.