Right click is not possible, because that is already taken for "show tooltip" (if tooltip delay is set to 0)

Ctrl+Click might be possible.

Ctrl+Click might be possible.

Ctrl + Click to [Skip] button is already binded as skipping a certain order.

I'm not married to right-click and it appears Ctrl-Click is also occupied.

So - shift-Click perhaps?

Or probably easier (and easier to remember) - split the Skip button into two adjacent buttons, Skip-down which performs identically to the current Skip button and Skip-up which also acts identically to the current Skip button except that it moves the current-order backwards in the list, not forwards.

So - shift-Click peraps?

Most Shift combined commands stand for estimating its cost, so I think Shift+click is not quite great.

Ctrl-Click already allows you to skip to an arbitrary order, it is not necessary to repeatedly press the skip button.
Select the order you want to skip to and then Ctrl-Click skip.

That's a much better solution, thanks for that @JGRennison :)

So - let's re-state the situation:

You can move the order pointer to any position in the list (forward or backward) by selecting the order and Ctrl-clicking the Skip button.

You can move the order pointer forward one position by clicking the Skip button.

You can move the order pointer back one position by following the select and Ctrl-click ceremony.

Right-click, shift-click and Ctrl-click on the Skip button are all occupied, and splitting the Skip button is too complex.

Since there is a way to move back one, there is no possibility of improving the situation.

How 'bout you cowpokes go sashay down to th'O.K. corral.

Now what's a good-lookin' white-hat to do when even the Marshall's out gunnin' for him?

Obvious! Ask Yoda.

Used here pgdn and pgup are not. Them to move one position down or up use.
. Hrmmm.