re = /(\/CIP3AdmJobName *\()([^\)]+)(\)[^\n]+)\n([^\(]+\()([^\)]+)/
str = '%!PS-Adobe-3.0
%%CIP3-File Version 2.1
%-Cip3-PPF-(RD16-2015-11-09)
%Mirror:1 Rotation:0
%PPFOnly-Mode
%ASCII-HEX-Imagedata
%-------------------------------------------
% Sheet
%-------------------------------------------
CIP3BeginSheet
/CIP3AdmJobCode (686708) def
/CIP3AdmJobName (686708) def
/CIP3AdmSheetName (Sig-2) def
%No TypeOfScreen
/CIP3AdmCreationTime (Tue Feb 07 14:41:38 2017) def
/CIP3AdmSheetLay /Left def
/CIP3AdmPaperGrammage 56.0 def
/CIP3AdmPaperThickness 0.051 mm def
%No /CIP3AdmPaperColor <-InData
/CIP3TransferFilmCurveData [0.0 0.0 1.0 1.0] def
/CIP3TransferPlateCurveData [0.0 0.0 1.0 1.0] def
/CIP3AdmPSExtent [2763.77953 1734.80315] def
/CIP3AdmPaperExtent [ 2412.00000000 1638.00000000 ] def
/CIP3AdmPaperTrf [ 1 0 0 1 -175.88976378 -63.77940283 ] def'
subst = '$1$2-$5$3\\n$4$5'
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