The most common and most likely answer to this crossword clue is the 9 letter word CO-DRIVER
I've seen this crossword clue in The Guardian
C
O
-
D
R
I
V
E
R
More clues leading to the result CO-DRIVER
Buddy explains!
The straight part
We know that "Helper on the way" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case helper on the way = co-driver.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.