Very expert about computer network - one's used to screen (7)
I believe the answer is:
valance
'one's used to screen' is the definition.
I can't judge whether this definition defines the answer.
'very expert about computer network' is the wordplay.
'very' becomes 'v' (abbreviation).
'expert' becomes 'ace' (ace can informally mean very good).
'about' is an insertion indicator.
'computer network' becomes 'LAN' (abbreviation for local-area network).
'ace' enclosing 'lan' is 'alance'.
'v'+'alance'='VALANCE'
Can you help me to learn more?
(Other definitions for valance that I've seen before include "hangover on bed" , "Decorative frill, on curtain say" , "Drapery used as cover" , "Decorative piece to conceal fixtures, of curtains perhaps" , "Hanging border of drapery" .)