re = /(([A-Z]+[ -]){1,})(([A-Z][a-z]+[ \-]){1,})\- ([0-9]{2}.[0-9]{2}.[0-9]{4}) - ([A|B|C])/m
str = 'ABBEY Chantelle - 08.11.1995 - A
ANAND Toni-Grace - 04.09.1999 - A
ADCOCK ALVEY James - 12.04.1992 - C
ADLINGTON-JONES Robin Jacob Sebastian - 15.02.1999 - B
AFZAL Kiera - 25.04.2000 - B
AHMED Nisar Abu Ben Adhem - 16.08.2002 - C
AIRE-DEANE Christopher-James - 06.01.1997 - B
AL-MISRI Yaqoob - 23.07.2004 - C
ASTER Lily-May - 01.04.2010 - B
McQUEEN Stephen - 02.02.2001 - A'
subst = '\\1\\t\\3\\t\\5\\t\\6'
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html