Dynamic collation support

For database functions, is there any way to manage collations besides
dynamic sql?  It doesn't look like there is but I thought I'd ask.

For example, I want to do something like:

DO
$$
DECLARE
  c name DEFAULT 'en_GB';
BEGIN
  SELECT * FROM foo ORDER BY a COLLATE c;
END;
$$;

and not

DO
$$
DECLARE
  c name DEFAULT 'en_GB';
BEGIN
  EXECUTE 'SELECT * FROM foo ORDER BY a COLLATE ' || quote_ident(c);
END;
$$;

I understand this would disable all index supported sorting; that's ok.

Not being able to specify collation in a parameterized manner presents
some issues...I'm curious if there are workarounds.

merlin