Expressing warm feelings towards underground money collector (7,4)

I believe the answer is:

wishing well

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'feelings towards underground money collector' is the definition.
I can't tell whether this definition defines the answer.

'expressing warm' is the wordplay.
'expressing' becomes 'wishing' (wishing is a kind of expressing).
'warm' becomes 'well' (I can't justify this - if you can you should believe this answer much more).
'wishing'+'well'='WISHING-WELL'

Can you help me to learn more?

I've seen this clue in The Times.

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