Good suggestions and code so far. Here is an alternate way. Here is a biterscript (biterscripting script). var str input, output; cat "txtsetup.sif" > $input # Extract everything upto "[SourceDisksFiles]\n" stex "^[SourceDisksFiles]\n^]" $input > $output # Add "example.dll = 1,,,,,,3_,2,0,0,,1,2\n" echo "example.dll = 1,,,,,,3_,2,0,0,,1,2\n" >> $output # Add remaining portion of $input echo $input >> $output # Write file back. echo $output > "txtsetup.sif" biterscripting scripting or batch language is free at http://www.biterscripting.com . Sen