I don't understand why it should be moving around. Have you got your
justification settings set to alter the width of the glyphs and the
spacing between letters? If so, you could set it to not allow
inter-letter spacing and glyph width to change to avoid it moving (and
also for a more traditional typeset look!)
But in any case it's strange to me that it should change the relative
position of the dot of those letters -- if the paragraph composer
applies an adjustment, it does so evenly to the entire line, so it's
weird that the dot should be moving.
The way I would do this is pretty much like you're doing -- apply some
drastic kerning and create character styles for each glyph that needs
individual treatment. Then just copy and paste whenever you need that
combination. (You could make a grep style, but unless this is appearing
in every paragraph, that's probably overkill.)
Which font are you using? Always the same one?
I'd also want to know what font you are using - because if your font doesn't have a combining dot above, then you should switch to a font that did have said glyph if at all possible. I'd use a font that had a combining dot above, then I'd key it in a V with a combining dot above. Kerning it into place is asking for trouble. I've manually kerned more diacritical marks into place than I care to admit (e.g. vast amounts of Vietnamese in fonts without Vietnamese support), and there are four or five ways that it can blow up in your face.
I'd go a step further and apply all these styles (including probably adding a no break attibute) as GREP styles inthe paragraph styles.
Thanks for your help, but I just created it in Illustrator and imported it as an inline graphic. Was quicker and better looking than I thought.