Module hooks/calling a specific hook

In a module I might have more than one hook registered. eg. comments,
hitcount & ratings.
Elsewhere when I call the hooks, is it possible to just call one in
particular? The reason being that at a particular point in the display I
might want to only display ratings.

- I realise that xarModCallHooks returns an assoc array with keys of called
hooks and that I can assign the key for the hooked output that I want.
However, what I really want to do is just call one hook as part of getting
the hook output.