Policeman and clergyman stand above common CEO (8-7)

I believe the answer is:

director-general

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'above common ceo' is the definition.
The definition suggests a singular noun which matches the answer.

'policeman and clergyman stand' is the wordplay.
'policeman' becomes 'di' (abbreviation for Detective Inspector).
'and' is a charade indicator (letters next to each other).
'clergyman' becomes 'rector' (rector is a kind of clergyman).
'stand' becomes 'general' (I can't justify this - if you can you should give a lot more credence to this answer).
'di'+'rector'+'general'='DIRECTOR-GENERAL'

Can you help me to learn more?

I've seen this clue in The Independent.

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