Log you could make treen from (5)
I believe the answer is:
enter
'log' is the definition.
(as in logging or entering information to a record)
'could make treen from' is the wordplay.
'treen' anagrams to 'ENTER'.
However, I am unsure how the anagram is indicated.
'you' acts as a link.
Can you help me to learn more?
(Other definitions for enter that I've seen before include "Register formally as a participant" , "Move into" , "Come/go in" , "Break in" , "Go in - set down" .)