Extract a field in a string collection

Hi guys,

From a .csv file, I want to extract the last field (say it's $15, or,
I guess, $NF) and make it like:
'12345', '23456', '34567' (comma separated strings).
The purpose is to use the list in a select request in the WHERE clause
(WHERE field IN ('12345', '23456', '34567').
The IN range would be therefore the file the AWK will sent the values
to.

Thanks,

Radu