Casting expert put in to secure HK film star (9)
I believe the answer is:
enchanter
'hk film star' is the definition.
I can't tell whether this definition defines the answer.
'casting expert put in to secure' is the wordplay.
'casting expert' becomes 'chan' (I can't justify this - if you can you should give a lot more credence to this answer).
'put in' becomes 'enter' (I've seen this in another clue).
'to secure' is an insertion indicator (inserted letters are secured inside).
'chan' going inside 'enter' is 'ENCHANTER'.
Can you help me to learn more?
(Other definitions for enchanter that I've seen before include "One charming" , "magician" , "siren, possibly" .)