Officer from company leading unit between lines (7)
I believe the answer is:
colonel
'officer' is the definition.
(colonel is a kind of officer)
'company leading unit between lines' is the wordplay.
'company' becomes 'co' (abbreviation).
'leading unit' becomes 'one' ('one' can be a synonym of 'unit'. I am not sure about the 'leading' bit.**).
'between' is an insertion indicator.
'lines' becomes 'll' (I've seen this in other clues).
'one' placed inside 'll' is 'lonel'.
'co'+'lonel'='COLONEL'
'from' is the link.
Can you help me to learn more?
(Other definitions for colonel that I've seen before include "Senior army officer" , "Military rank" , "soldier" , "Comissioned military officer" , "Commissioned officer" .)