Go forward with victory in a foxtrot? (7)
I believe the answer is:
advance
'go forward' is the definition.
'victory in a foxtrot?' is the wordplay.
'victory' becomes 'v'.
'in' is an insertion indicator.
'foxtrot?' becomes 'dance' (foxtrot is a kind of dance).
'a'+'dance'='adance'
'v' put inside 'adance' is 'ADVANCE'.
'with' acts as a link.
(Other definitions for advance that I've seen before include "Payment ahead of due date (1'7)" , "Make headway" , "Forward - loan - make progress" , "Forward - loan - increase" , "Promote" .)