Hunters' call can count on head office (5-2)
I believe the answer is:
tally-ho
'hunters' call' is the definition.
'tally ho' can be an answer for 'call' (I've seen this before). I am unsure of the 'hunters'' bit.
'count on head office' is the wordplay.
'count' becomes 'tally' (synonyms).
'on' is a charade indicator (letters next to each other).
'head office' becomes 'HO'.
'tally'+'ho'='TALLY-HO'
'can' is the link.
Can you help me to learn more?
(Other definitions for tally-ho that I've seen before include "Huntsman's cry" , ""I've seen the fox!"" , "Come on, hounds!" , "Hunter's cry" , "Hunt cry" .)