Connect with a number in that network (6)
I believe the answer is:
attach
'connect' is the definition.
(I know that connect is a more specific form of the action enter)
'a number in that network' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'number' could be 'c' (C is an example) and 'c' is present in the answer.
an anagram of 'that' is 'ttah' which is present in the left over letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'with' acts as a link.
Can you help me to learn more?
(Other definitions for attach that I've seen before include "Stick" , "Secure" , "Affix, connect" , "Conjoin, affix" , "Tag on" .)