Sorry, but this method won't work.

When a style is associated with an outline level in an Outline Numbering Scheme, this method only updates the associated style with a LEFT tab stop. If you want a RIGHT tab stop, you have to modify the style.

When a style is NOT associated with an outline level, this method will create a tab stop (using direct formatting) in the paragraph. Even if one was able to create a RIGHT tab this way, removing a style from one level in a numbering scheme is inadvisable... the only way to apply that numbering (it's not associated with a style, remember) is to apply the PRIOR style, then use the tab to navigate to the next numbering setting in the scheme. You may get the right number (temporarily) but the paragraph has the wrong style, and will be adversely affected if that style is modified. In fact, if the style is reapplied, the prior level numbering is also reapplied.

oops!

That would totally mess up the document, so much so that I'm not sure why Word even lets you save the Outline scheme with a style missing on a Level in the middle of the sequence. I think I've asked for that enhancement a bunch of times! HAHAHAH!