require 'rubygems'
require 'fastercsv'

#table.csv:
#foo,bar,ABC/123-456
#bar,foo,BCD/987-654

csv = File.new("new.csv","w+")

File.readlines("table.csv").each do |row|
  cols = row.split(',')
  ref = cols[2].gsub(/\/.*/){}
  csv.puts "#{row.gsub(/\n/){}},#{ref}"
end

csv.close